JP7416358B2 - Non-destructive testing method and testing equipment - Google Patents

Description

The present invention relates to a non-destructive inspection method and an inspection device for inspecting whether or not steel materials buried in a concrete body are damaged from the outside without destroying the concrete body.

BACKGROUND ART Conventionally, non-destructive testing methods have been known for testing the presence or absence of fractures in steel provided within a concrete body. For example, the nondestructive testing method described in Japanese Patent No. 3734822 (Patent Document 1) moves a permanent magnet on the surface of a concrete body along the longitudinal direction of reinforcing bars to be inspected that are buried in the concrete body. As a result, the steel material is magnetized, and the magnetic flux density leaking from the surface of the concrete body is measured by two magnetic sensors placed at a certain distance in the longitudinal direction of the steel material. Furthermore, a method is employed in which the difference between the two obtained measured values and the change in the differential value are calculated, and where the difference exceeds a certain threshold value, it is determined that there is a suspicion of fracture. However, this judgment method requires a considerable amount of practical experience in determining the above-mentioned threshold value, and if the baseline (the straight line that serves as the standard for changes in the magnetic flux density waveform) is significantly tilted due to the magnetization conditions, or if the steel material to be inspected is If there is noise due to intersecting reinforcing bars, etc., which are present separately, there are problems in that it may be difficult to judge even for those with considerable practical experience.

To solve this problem, we compared the state of the rate of change of magnetic flux density with data obtained by mock-up measurements using a reinforced concrete structure simulated in advance (the fracture position of the reinforcing bars is known), and compared it to some extent qualitatively (for example, If we try to inspect the presence or absence of fractures in reinforcing bars using rules of thumb, AI technology, machine learning, etc., it would be necessary to collect a large amount of data over a huge amount of time in order to ensure accuracy. There is a problem in terms of simplifying and speeding up the process.

In addition, since the presence or absence of a break is determined by comparing the pre-learning data with the data obtained through measurement, there is a problem that, for example, if a case that does not exist in the learning database occurs, an appropriate judgment cannot be made. There was also.

Patent No. 3734822

Therefore, the present invention has been made for the purpose of proposing a non-destructive testing method and a non-destructive testing device that quantitatively determine the presence and/or location of damage to steel materials within a concrete body without destroying the concrete body. It is something.

The present invention employs the following configuration as a specific means for solving this problem.

The nondestructive testing method of the first invention of the present application includes magnetizing the steel material to be inspected from the outside of the concrete body in which the steel material to be inspected is buried, using a magnet, and then measuring the magnetic flux density of the concrete body using a magnetic sensor. This is a non-destructive testing method for detecting the presence and/or position of a damaged part in the above-mentioned steel material to be inspected,
a magnetization step of arranging the magnetized surface of the magnet close to the surface of the concrete body and then magnetizing the steel material to be inspected along its longitudinal direction by moving it appropriately or without moving it;
After arranging a magnetic sensor unit having a plurality of magnetic sensors arranged in a row close to the surface of the concrete body with the direction in which the magnetic sensors are arranged substantially perpendicular to the longitudinal direction of the steel material to be inspected, A magnetic flux density measuring step of measuring the magnetic flux density of the steel material to be inspected by or without moving the steel material in the longitudinal direction;
A raw contour map generation process that generates a magnetic flux density contour map based on the magnetic flux density measured in the magnetic flux density measurement step, and a flattened contour map by subtracting a linear change in the longitudinal direction of the magnetic flux density from the raw contour map. a smoothing process to obtain a smoothed contour map, a smoothing process to obtain a smoothed contour map by smoothing the flattened contour map in the longitudinal direction, and a first-order or multiple-order differential in the longitudinal direction for the smoothed contour map. At least the above-mentioned raw contour map generation process and the above-mentioned flattening process. or at least the above raw contour map generation process, the flattening process and the smoothing process, or at least the above raw contour map generation process and the differentiation process, or at least the above raw contour map generation process and a contour map processing step of performing the flattening processing and integration processing;
Compare any one of the flattened contour map, smoothed contour map, differential contour map, and integral contour map with a predetermined criterion value to determine the presence and/or location of damaged parts in the steel material to be inspected. and a determination step of
The above judgment standard value is
The direction of the magnetic flux within the steel material to be inspected is the longitudinal direction of the steel material to be inspected, and the magnetic flux density component in a direction substantially orthogonal to the surface of the concrete body, or its differential or integral in the longitudinal direction, is substantially orthogonal to the surface of the concrete body. When drawing a contour map with the direction away from the steel material being inspected as positive and the opposite direction as negative,
In the judgment using the flattened contour map or the smoothed contour map, the maximum and minimum parts of the contour line appear sequentially in the longitudinal direction of the steel to be inspected, and the maximum and minimum parts are located in the longitudinal direction of the steel to be inspected. When in the direction it is bipolar, antisymmetrical about the orthogonal axis, and in the orthogonal direction, it is unimodal, symmetrical about the longitudinal axis,
In the judgment using the above differential contour map, in the second order or (2+4n) order differential among the even number of differentiations, the minimum and maximum parts of the contour line appear sequentially in the longitudinal direction of the steel material to be inspected, and the minimum and maximum parts appear sequentially in the longitudinal direction of the steel material to be inspected. When the part is bipolar in the longitudinal direction of the steel to be inspected, which is antisymmetrical to the orthogonal direction axis, and in the orthogonal direction, it is a monomodal shape that is symmetrical to the longitudinal direction (n is a natural number),
Furthermore, in the 4th or (4+4n) order differential among the even-numbered differentiations, the maximum and minimum parts of the contour line appear sequentially in the longitudinal direction of the steel material to be inspected, and the maximum and minimum parts of the contour line appear in the longitudinal direction of the steel material to be inspected. When it becomes a bipolar shape that is antisymmetric about the orthogonal direction axis, and a unimodal shape that is symmetric about the longitudinal axis in the orthogonal direction (n is a natural number),
Each of these values is preset to indicate that the intersection of the longitudinal axis and the orthogonal axis of the steel material to be inspected is a damaged portion of the steel material to be inspected,
Or, the above judgment standard value is
The direction of the magnetic flux within the steel material to be inspected is a direction opposite to the longitudinal direction of the steel material to be inspected, and the magnetic flux density component in a direction approximately perpendicular to the surface of the concrete body, or its differential or integral in the longitudinal direction is the surface of the concrete body. When drawing a contour map with the direction substantially perpendicular to the steel material and moving away from the steel material to be inspected as positive and the opposite direction as negative,
In the judgment using the flattened contour map or the smoothed contour map, the minimum and maximum parts of the contour line appear sequentially in the longitudinal direction of the steel to be inspected, and the minimum and maximum parts are located in the longitudinal direction of the steel to be inspected. When in the direction it is bipolar, antisymmetrical about the orthogonal axis, and in the orthogonal direction, it is unimodal, symmetrical about the longitudinal axis,
In the judgment using the above differential contour map, in the second order or (2+4n) order differential among the even number of differentiations, the maximum and minimum parts of the contour line appear sequentially in the longitudinal direction of the steel material to be inspected, and the maximum and minimum parts appear sequentially in the longitudinal direction of the steel material to be inspected. When the part is bipolar in the longitudinal direction of the steel to be inspected, which is antisymmetrical to the orthogonal direction axis, and in the orthogonal direction, it is a monomodal shape that is symmetrical to the longitudinal direction (n is a natural number),
Furthermore, in the 4th or (4+4n) order differential among the even-numbered differentiations, the minimum and maximum parts of the contour lines appear sequentially in the longitudinal direction of the steel material to be inspected, and the minimum and maximum parts are in the longitudinal direction of the steel material to be inspected. When it becomes a bipolar shape that is antisymmetric about the orthogonal direction axis, and a unimodal shape that is symmetric about the longitudinal axis in the orthogonal direction (n is a natural number),
Each of these values is characterized in that the value is preset to indicate that the intersection of the longitudinal axis and the orthogonal axis of the steel material to be inspected is a damaged portion of the steel material to be inspected.

The non-destructive testing method of the second invention of the present application includes magnetizing the steel material to be inspected from the outside of the concrete body in which the steel material to be inspected is buried using a magnet, and then measuring the magnetic flux density of the concrete body using a magnetic sensor. This is a non-destructive testing method for detecting the presence and/or position of a damaged part in the above-mentioned steel material to be inspected,
a magnetization step of arranging the magnetized surface of the magnet close to the surface of the concrete body and then magnetizing the steel material to be inspected along its longitudinal direction by moving it appropriately or without moving it;
After arranging a magnetic sensor unit having a plurality of magnetic sensors arranged in a row close to the surface of the concrete body with the direction in which the magnetic sensors are arranged substantially perpendicular to the longitudinal direction of the steel material to be inspected, A magnetic flux density measuring step of measuring the magnetic flux density of the steel material to be inspected by or without moving the steel material in the longitudinal direction;
A raw contour map generation process that generates a magnetic flux density contour map based on the magnetic flux density measured in the magnetic flux density measurement step, and a flattened contour map by subtracting a linear change in the longitudinal direction of the magnetic flux density from the raw contour map. a smoothing process to obtain a smoothed contour map, a smoothing process to obtain a smoothed contour map by smoothing the flattened contour map in the longitudinal direction, and a first-order or multiple-order differential in the longitudinal direction for the smoothed contour map. At least the above-mentioned raw contour map generation process and the above-mentioned flattening process. or at least the above raw contour map generation process, the flattening process and the smoothing process, or at least the above raw contour map generation process and the differentiation process, or at least the above raw contour map generation process and a contour map processing step of performing the flattening processing and integration processing;
Compare any one of the flattened contour map, smoothed contour map, differential contour map, and integral contour map with a predetermined criterion value to determine the presence and/or location of damaged parts in the steel material to be inspected. and a determination step of
The above judgment standard value is
The direction of the magnetic flux within the steel material to be inspected is the longitudinal direction of the steel material to be inspected, and the magnetic flux density component in a direction substantially orthogonal to the surface of the concrete body, or its differential or integral in the longitudinal direction, is substantially orthogonal to the surface of the concrete body. When drawing a contour map with the direction away from the steel material being inspected as positive and the opposite direction as negative,
In the determination using the above differential contour map, the minimum part of the contour line is the first or (1+4n) order of odd-order differentiation, and the maximum part of the contour line is the third-order or (3+4n) order of odd-order differentiation. When each of the above-mentioned steel materials to be inspected has a symmetrical single peak shape in the longitudinal direction with respect to the orthogonal direction axis and in the orthogonal direction with respect to the longitudinal direction axis (n is a natural number),
In addition, in the judgment using the above integral contour map, the maximum part of the contour line in the first-order integral is symmetrical in the longitudinal direction of the steel material to be inspected with respect to the orthogonal direction axis, and in the orthogonal direction with respect to the longitudinal direction axis. When it is unimodal,
Each of these values is preset to indicate that the intersection of the longitudinal axis and the orthogonal axis of the steel material to be inspected is a damaged portion of the steel material to be inspected,
Or, the above judgment standard value is
The direction of the magnetic flux within the steel material to be inspected is a direction opposite to the longitudinal direction of the steel material to be inspected, and the magnetic flux density component in a direction approximately perpendicular to the surface of the concrete body, or its differential or integral in the longitudinal direction is the surface of the concrete body. When drawing a contour map with the direction substantially perpendicular to the steel material and moving away from the steel material to be inspected as positive and the opposite direction as negative,
In the determination using the above differential contour map, the maximum part of the contour line is the first or (1+4n) order of odd-order differentiation, and the minimum part of the contour line is the third-order or (3+4n) order of odd-order differentiation. When each of the above-mentioned steel materials to be inspected has a symmetrical unimodal shape in the longitudinal direction with respect to the orthogonal direction axis and in the orthogonal direction with respect to the longitudinal direction axis (n is a natural number),
In addition, in the judgment using the above integral contour map, the minimum part of the contour line in the first-order integral is symmetrical in the longitudinal direction of the steel material to be inspected with respect to the orthogonal direction axis, and in the orthogonal direction with respect to the longitudinal direction axis. When it is unimodal,
Each of these is characterized by a value set in advance to indicate that the intersection of the longitudinal axis and the orthogonal axis of the steel material to be inspected is a damaged portion of the steel material to be inspected.

Here, the steel material to be inspected is reinforcing bars that are often used in general reinforced concrete structures. The material is not limited to a round bar with a circular cross-sectional shape or a deformed steel bar with a protrusion on the surface, but may also be a steel bar with a rectangular or other polygonal cross-sectional shape, or an H-beam steel bar. In addition, it may be a hollow steel pipe used for water flow or ventilation, and it may also be made of prestressed steel materials such as prestressed steel rods, prestressed steel wires, or prestressed steel stranded wires used in prestressed concrete construction methods, or these may be used inside. It may be a sheath pipe used through the pipe or a PC steel material inside the sheath pipe.

In addition, damage to steel refers to not only the state where the steel is completely broken, but also, for example, in the case of steel made of a bundle of many steel wires such as PC steel wire or PC stranded wire, damage to the steel material refers to the state where the steel material is completely broken. This also includes cases where a part of the pipe is broken.

When magnetizing the steel to be inspected in the above magnetization process, in order to place the magnetized surface of the magnet close to the surface of the concrete body, temporarily place the magnetized surface of the magnet at a predetermined position near the surface of the concrete body. The magnetized surface of the magnet does not necessarily need to be brought into contact with the surface of the concrete body, nor does it need to be stationary. Furthermore, if the magnet is small, the steel to be inspected may be magnetized by moving the magnetized surface of the magnet along the longitudinal direction of the steel to be inspected; if the magnet is large, the magnet By arranging the magnetization surface at one location along the longitudinal direction of the steel material to be inspected without moving the magnetization surface thereof, the steel material to be inspected may be magnetized over a wide range.

The magnetized surface of a magnet refers to the side of the magnet that is closest to the surface of the concrete body when magnetizing steel, and its shape is not limited to a single plane. It may be any electromagnet.

In addition, in the magnetic flux density measurement process, in order to place the magnetic sensor close to the surface of the concrete body, as in the case of the above magnet, it is necessary to temporarily bring the magnetic sensor close to a predetermined position near the surface of the concrete body. Often, there is no need for it to be in direct contact with the surface of the concrete body, and there is no need for it to be stationary.

In addition, in order to determine the magnetic flux density along the longitudinal direction of the steel material to be inspected, it is necessary to measure the magnetic flux density not only in the inspection range of the damaged part of the steel material to be inspected, but also in the surrounding area as necessary. Therefore, in the present invention, a magnetic sensor unit in which a plurality of magnetic sensors are arranged in a row at a predetermined interval is arranged with the direction in which the magnetic sensors are arranged substantially perpendicular to the longitudinal direction of the steel material to be inspected, and the magnetic sensor unit is used to measure the magnetic flux density. It was designed to measure.

Furthermore, as shown in FIG. 27, for example, the contour map can be used to plot the values of the response variables in the magnetic flux density waveform (in the case of the present invention, the values in the direction perpendicular to the surface of the concrete body (Z-axis direction)) on orthogonal coordinates. It is expressed as a contour line in the system, and the correspondence relationship between the contour line diagram and the magnetic flux density waveform is as follows.

Figure (a) shows, as an example, the relationship between a smoothed contour map and a magnetic flux density waveform diagram, which has been subjected to smoothing processing to reduce noise from cross reinforcing bars, etc. that exist separately from the steel material to be inspected, through filtering, etc. When the direction of magnetic flux due to magnetization is in the longitudinal direction of the reinforcing steel, in the smoothed contour map, the maximum and minimum parts located on both sides of the Y-direction axis n are "maximum part → minimum part" The maximum part and the minimum part correspond to the maximum part and the minimum part of the bipolar magnetic flux density waveform L1 traveling in the longitudinal direction of the reinforcing steel, respectively. In addition, when the magnetic flux direction is opposite to the longitudinal direction of the reinforcing steel, the magnetic flux density waveform becomes the magnetic flux density waveform L2. The section itself is the opposite.

Figure (b) shows, as an example, the relationship between the first-order differential contour map and the magnetic flux density waveform diagram after first-order differential processing. The first-order differential contour map is symmetrical about both the Y-direction axis n and the X-direction axis m, and the minimum part is on the intersection of the As a result, the magnetic flux density waveform becomes a single peak waveform diagram L3 having a minimum portion. Note that in the opposite direction, the waveform diagram L4 is a single peak with a maximum part, so in the first-order differential contour diagram, the maximum part and the minimum part are in opposite directions, corresponding to the direction of the magnetic flux.

The nondestructive testing method of the third invention of the present application includes magnetizing the steel material to be inspected from the outside of the concrete body in which the steel material to be inspected is buried using a magnet, and then measuring the magnetic flux density of the concrete body using a magnetic sensor. A non-destructive testing method for detecting the presence and/or position of damaged parts in the above-mentioned steel material to be inspected,
a magnetization step of arranging the magnetized surface of the magnet close to the surface of the concrete body and then magnetizing the steel material to be inspected along its longitudinal direction by moving it appropriately or without moving it;
At least one magnetic sensor unit including a plurality of magnetic sensors arranged in a row and another magnetic sensor unit are arranged in such a manner that the direction in which each magnetic sensor is arranged is substantially perpendicular to the longitudinal direction of the steel material to be inspected, and After fixing the relative positions of both magnetic sensor units so as to move away from the surface of the concrete object sequentially, the magnetic flux density of the steel material to be inspected can be determined by moving or not moving in the longitudinal direction of the steel material to be inspected. a magnetic flux density measurement step for measuring the
a first processing step of generating raw contour maps of magnetic flux density based on the magnetic flux densities respectively measured by the one magnetic sensor unit and the other magnetic sensor unit in the magnetic flux density measuring step; A flattening process is performed to obtain a flattened contour map by subtracting a linear change in the magnetic flux density in the longitudinal direction, and a smoothing process is performed to obtain a smoothed contour map by smoothing each of the flattened contour maps in the longitudinal direction. a second processing step in which the respective smoothed contour maps are combined by calculation based on the burial depth to obtain a composite smoothed contour map; Perform differentiation processing to obtain differential contour maps by differentiating the first floor or multiple floors in the direction, and calculate each of the differential contour maps based on the buried depth of the steel material to be inspected from the surface of the concrete body. A third processing step is performed to synthesize a composite differential contour map, and an integral process is performed to perform first-order integration in the longitudinal direction on each of the smoothed contour maps to obtain an integral contour map. Of the fourth processing step of synthesizing each of the above-mentioned integral contour maps based on the calculation to obtain a composite integral contour map, at least the above-mentioned first processing step and the above-mentioned second processing step are performed, or at least the above-mentioned a contour map processing step of performing a first processing step and the third processing step, or at least performing the first processing step and the fourth processing step;
Judgment to determine the presence or absence and/or position of damaged parts in the steel material to be inspected by comparing any of the composite smoothed contour map, composite differential contour map, and composite integral contour map with a predetermined criterion value. including the process,
The above judgment standard value is
The direction of the magnetic flux within the steel material to be inspected is the longitudinal direction of the steel material to be inspected, and the magnetic flux density component in a direction substantially orthogonal to the surface of the concrete body, or its differential or integral in the longitudinal direction, is substantially orthogonal to the surface of the concrete body. When drawing a contour map with the direction away from the steel material being inspected as positive and the opposite direction as negative,
In the determination using the composite smoothed contour map, the maximum and minimum parts of the contour lines appear sequentially in the longitudinal direction of the steel to be inspected, and the maximum and minimum parts are orthogonal to each other in the longitudinal direction of the steel to be inspected. When it becomes a bipolar shape that is antisymmetric about the axis and a unimodal shape that is symmetric about the longitudinal axis in the orthogonal direction,
In the judgment using the above composite differential contour map, in the second order or (2+4n) order differential among the even-numbered differentials, the minimum and maximum parts of the contour line appear sequentially in the longitudinal direction of the steel material to be inspected, and the minimum part and When the maximum part has a bipolar shape that is antisymmetrical to the orthogonal direction axis in the longitudinal direction of the steel to be inspected, and a single peak shape that is symmetrical to the longitudinal direction in the orthogonal direction (n is a natural number),
Furthermore, in the 4th or (4+4n) order differential among the even-numbered differentiations, the maximum and minimum parts of the contour line appear sequentially in the longitudinal direction of the steel material to be inspected, and the maximum and minimum parts of the contour line appear in the longitudinal direction of the steel material to be inspected. When it becomes a bipolar shape that is antisymmetric about the orthogonal direction axis, and a unimodal shape that is symmetric about the longitudinal axis in the orthogonal direction (n is a natural number),
Each of these values is preset to indicate that the intersection of the longitudinal axis and the orthogonal axis of the steel material to be inspected is a damaged portion of the steel material to be inspected,
Or, the above judgment standard value is
The direction of the magnetic flux within the steel material to be inspected is a direction opposite to the longitudinal direction of the steel material to be inspected, and the magnetic flux density component in a direction approximately perpendicular to the surface of the concrete body, or its differential or integral in the longitudinal direction is the surface of the concrete body. When drawing a contour map with the direction substantially perpendicular to the steel material and moving away from the steel material to be inspected as positive and the opposite direction as negative,
In the judgment using the composite smoothed contour map, the minimum and maximum parts of the contour line appear sequentially in the longitudinal direction of the steel to be inspected, and the minimum and maximum parts are orthogonal to each other in the longitudinal direction of the steel to be inspected. When it becomes a bipolar shape that is antisymmetric about the axis and a unimodal shape that is symmetric about the longitudinal axis in the orthogonal direction,
In the judgment using the composite differential contour map, the maximum and minimum parts of the contour line appear sequentially in the longitudinal direction of the steel material to be inspected in the second order or (2+4n) order of the even-numbered differentiation, and When the minimum part has a bipolar shape that is antisymmetrical to the orthogonal direction axis in the longitudinal direction of the steel material to be inspected, and a unimodal shape that is symmetrical to the longitudinal direction in the orthogonal direction (n is a natural number),
Furthermore, in the 4th or (4+4n) order differential among the even-numbered differentiations, the minimum and maximum parts of the contour lines appear sequentially in the longitudinal direction of the steel material to be inspected, and the minimum and maximum parts are in the longitudinal direction of the steel material to be inspected. When it becomes a bipolar shape that is antisymmetric about the orthogonal direction axis, and a unimodal shape that is symmetric about the longitudinal axis in the orthogonal direction (n is a natural number),
Each of these values is characterized in that the value is preset to indicate that the intersection of the longitudinal axis and the orthogonal axis of the steel material to be inspected is a damaged portion of the steel material to be inspected.

The non-destructive testing method of the fourth invention of the present application includes magnetizing the steel material to be inspected with a magnet from the outside of the concrete body in which the steel material to be inspected is buried, and then measuring the magnetic flux density of the concrete body with a magnetic sensor. A non-destructive testing method for detecting the presence and/or position of damaged parts in the above-mentioned steel material to be inspected,
a magnetization step of arranging the magnetized surface of the magnet close to the surface of the concrete body and then magnetizing the steel material to be inspected along its longitudinal direction by moving it appropriately or without moving it;
At least one magnetic sensor unit including a plurality of magnetic sensors arranged in a row and another magnetic sensor unit are arranged in such a manner that the direction in which each magnetic sensor is arranged is substantially perpendicular to the longitudinal direction of the steel material to be inspected, and After fixing the relative positions of both magnetic sensor units so as to move away from the surface of the concrete object sequentially, the magnetic flux density of the steel material to be inspected can be determined by moving or not moving in the longitudinal direction of the steel material to be inspected. a magnetic flux density measurement step for measuring the
a first processing step of generating raw contour maps of magnetic flux density based on the magnetic flux densities respectively measured by the one magnetic sensor unit and the other magnetic sensor unit in the magnetic flux density measuring step; A flattening process is performed to obtain a flattened contour map by subtracting a linear change in the magnetic flux density in the longitudinal direction, and a smoothing process is performed to obtain a smoothed contour map by smoothing each of the flattened contour maps in the longitudinal direction. a second processing step in which the respective smoothed contour maps are combined by calculation based on the burial depth to obtain a composite smoothed contour map; Perform differentiation processing to obtain differential contour maps by differentiating the first floor or multiple floors in the direction, and calculate each of the differential contour maps based on the buried depth of the steel material to be inspected from the surface of the concrete body. A third processing step is performed to synthesize a composite differential contour map, and an integral process is performed to perform first-order integration in the longitudinal direction on each of the smoothed contour maps to obtain an integral contour map. Of the fourth processing step of synthesizing each of the above-mentioned integral contour maps based on the calculation to obtain a composite integral contour map, at least the above-mentioned first processing step and the above-mentioned second processing step are performed, or at least the above-mentioned a contour map processing step of performing a first processing step and the third processing step, or at least performing the first processing step and the fourth processing step;
Judgment to determine the presence or absence and/or position of damaged parts in the steel material to be inspected by comparing any of the composite smoothed contour map, composite differential contour map, and composite integral contour map with a predetermined criterion value. including the process,
The above judgment standard value is
The direction of the magnetic flux within the steel material to be inspected is the longitudinal direction of the steel material to be inspected, and the magnetic flux density component in a direction substantially orthogonal to the surface of the concrete body, or its differential or integral in the longitudinal direction, is substantially orthogonal to the surface of the concrete body. When drawing a contour map with the direction away from the steel material being inspected as positive and the opposite direction as negative,
In the judgment using the above synthetic differential contour map, the minimum part of the contour line is the first or (1+4n) order of the odd-order differentiation, and the maximum part of the contour line is the third-order or (3+4n) order of the odd-order differentiation. , when the longitudinal direction of the steel material to be inspected has a symmetrical single peak shape with respect to the orthogonal direction axis, and the orthogonal direction with respect to the longitudinal direction axis (n is a natural number),
In addition, in the judgment using the above composite integral contour map, the maximum part of the contour line in the first-order integral is symmetrical in the longitudinal direction of the steel material to be inspected with respect to the orthogonal direction axis, and in the orthogonal direction with respect to the longitudinal direction axis. When the shape is unimodal,
Each of these values is preset to indicate that the intersection of the longitudinal axis and the orthogonal axis of the steel material to be inspected is a damaged portion of the steel material to be inspected,
Or, the above judgment standard value is
The direction of the magnetic flux within the steel material to be inspected is a direction opposite to the longitudinal direction of the steel material to be inspected, and the magnetic flux density component in a direction approximately perpendicular to the surface of the concrete body, or its differential or integral in the longitudinal direction is the surface of the concrete body. When drawing a contour map with the direction substantially perpendicular to the steel material and moving away from the steel material to be inspected as positive and the opposite direction as negative,
In the judgment using the above composite differential contour map, the maximum part of the contour line is the first or (1+4n) order of odd-order differentiation, and the minimum part of the contour line is the minimum part of the third-order or (3+4n) order of odd-order differentiation. , when the longitudinal direction of the steel material to be inspected has a symmetrical single peak shape with respect to the orthogonal direction axis, and the orthogonal direction with respect to the longitudinal direction axis (n is a natural number),
In addition, in the judgment using the above composite integral contour map, the minimum part of the contour line in the first-order integral is symmetrical in both the longitudinal direction of the steel material to be inspected with respect to the orthogonal direction axis, and in the orthogonal direction with respect to the longitudinal direction axis. When the shape is unimodal,
Each of these is characterized by a value set in advance to indicate that the intersection of the longitudinal axis and the orthogonal axis of the steel material to be inspected is a damaged portion of the steel material to be inspected.

Here, the above-mentioned "embedding depth" is a known value obtained from a design drawing or actual measurement, or a calculated value obtained by calculation in the fifth invention of the present application, which will be described later.

A non-destructive testing method according to a fifth invention of the present application is such that, in the non-destructive testing method according to the third or fourth invention, the burying depth is determined between the first magnetic sensor unit and the other magnetic sensor unit in the magnetic flux density measuring step. Each raw contour map generated based on the magnetic flux density measured by the magnetic sensor unit, and each flattened contour map obtained by subtracting a linear change in the longitudinal direction of the magnetic flux density from each of the above raw contour maps. Each smoothed contour map obtained by smoothing in the longitudinal direction, each differential contour map obtained by performing one or more orders of differentiation in the longitudinal direction for each smoothed contour map, and each smoothed contour map The method is characterized in that it is calculated by calculation based on at least one of the integral contour maps obtained by first-order integration in the longitudinal direction for each contour map.

A non-destructive testing method according to a sixth invention of the present application is a non-destructive testing method according to the first, second , third, fourth or fifth invention, comprising:
In the above judgment process, the accuracy of the judgment result based on the comparison between the raw contour map, flattened contour map, smoothed contour map, differential contour map, and integral contour map and the above judgment reference value is verified, and then again. If it is determined that it is necessary to make a judgment, compare the above judgment standard values with another contour map different from the contour map used for the previous judgment to determine the presence or absence and/or location of damaged parts of the steel material to be inspected. It is characterized by re-judging.

The non-destructive testing device according to the seventh aspect of the present application is configured to magnetize the steel material to be inspected from outside of the concrete body in which the steel material to be inspected is buried using a magnet, and then measure the magnetic flux density of the concrete body using a magnetic sensor. A non-destructive testing device for detecting the presence and/or position of a damaged part in the steel material to be inspected,
A magnetizing unit including a magnet that magnetizes the steel material to be inspected along its longitudinal direction by or without moving the magnetized surface as appropriate after arranging it close to the surface of the concrete body;
After arranging a magnetic sensor unit having a plurality of magnetic sensors arranged in a row close to the surface of the concrete body with the direction in which the magnetic sensors are arranged substantially perpendicular to the longitudinal direction of the steel material to be inspected, a magnetic flux density measurement unit that measures the magnetic flux density of the steel material to be inspected by or without moving the steel material in the longitudinal direction;
A raw contour map generation process that generates a contour map of magnetic flux density based on the magnetic flux density measured by the magnetic flux density measurement unit, and a flattened contour map by subtracting a linear change in the longitudinal direction of the magnetic flux density from the raw contour map. a smoothing process to obtain a smoothed contour map, a smoothing process to obtain a smoothed contour map by smoothing the flattened contour map in the longitudinal direction, and a first-order or multiple-order differential in the longitudinal direction for the smoothed contour map. At least the above-mentioned raw contour map generation process and the above-mentioned flattening process. or at least the above raw contour map generation process, the flattening process and the smoothing process, or at least the above raw contour map generation process and the differentiation process, or at least the above raw contour map generation process and a contour map processing unit that performs the flattening process and the integration process;
Compare any one of the flattened contour map, smoothed contour map, differential contour map, and integral contour map with a predetermined criterion value to determine the presence and/or location of damaged parts in the steel material to be inspected. and a determination unit to
The above judgment standard value is
The direction of the magnetic flux within the steel material to be inspected is the longitudinal direction of the steel material to be inspected, and the magnetic flux density component in a direction substantially orthogonal to the surface of the concrete body, or its differential or integral in the longitudinal direction, is substantially orthogonal to the surface of the concrete body. When drawing a contour map with the direction away from the steel material being inspected as positive and the opposite direction as negative,
In the judgment using the flattened contour map or the smoothed contour map, the maximum and minimum parts of the contour line appear sequentially in the longitudinal direction of the steel to be inspected, and the maximum and minimum parts are located in the longitudinal direction of the steel to be inspected. When in the direction it is bipolar, antisymmetrical about the orthogonal axis, and in the orthogonal direction, it is unimodal, symmetrical about the longitudinal axis,
In the judgment using the above differential contour map, in the second order or (2+4n) order differential among the even number of differentiations, the minimum and maximum parts of the contour line appear sequentially in the longitudinal direction of the steel material to be inspected, and the minimum and maximum parts appear sequentially in the longitudinal direction of the steel material to be inspected. When the part is bipolar in the longitudinal direction of the steel to be inspected, which is antisymmetrical to the orthogonal direction axis, and in the orthogonal direction, it is a monomodal shape that is symmetrical to the longitudinal direction (n is a natural number),
Furthermore, in the 4th or (4+4n) order differential among the even-numbered differentiations, the maximum and minimum parts of the contour line appear sequentially in the longitudinal direction of the steel material to be inspected, and the maximum and minimum parts of the contour line appear in the longitudinal direction of the steel material to be inspected. When it becomes a bipolar shape that is antisymmetric about the orthogonal direction axis, and a unimodal shape that is symmetric about the longitudinal axis in the orthogonal direction (n is a natural number),
Each of these values is preset to indicate that the intersection of the longitudinal axis and the orthogonal axis of the steel material to be inspected is a damaged portion of the steel material to be inspected,
Or, the above judgment standard value is
The direction of the magnetic flux within the steel material to be inspected is a direction opposite to the longitudinal direction of the steel material to be inspected, and the magnetic flux density component in a direction approximately perpendicular to the surface of the concrete body, or its differential or integral in the longitudinal direction is the surface of the concrete body. When drawing a contour map with the direction substantially perpendicular to the steel material and moving away from the steel material to be inspected as positive and the opposite direction as negative,
In the judgment using the flattened contour map or the smoothed contour map, the minimum and maximum parts of the contour line appear sequentially in the longitudinal direction of the steel to be inspected, and the minimum and maximum parts are located in the longitudinal direction of the steel to be inspected. When in the direction it is bipolar, antisymmetrical about the orthogonal axis, and in the orthogonal direction, it is unimodal, symmetrical about the longitudinal axis,
In the judgment using the above differential contour map, in the second order or (2+4n) order differential among the even number of differentiations, the maximum and minimum parts of the contour line appear sequentially in the longitudinal direction of the steel material to be inspected, and the maximum and minimum parts appear sequentially in the longitudinal direction of the steel material to be inspected. When the part is bipolar in the longitudinal direction of the steel to be inspected, which is antisymmetrical to the orthogonal direction axis, and in the orthogonal direction, it is a monomodal shape that is symmetrical to the longitudinal direction (n is a natural number),
Furthermore, in the 4th or (4+4n) order differential among the even-numbered differentiations, the minimum and maximum parts of the contour lines appear sequentially in the longitudinal direction of the steel material to be inspected, and the minimum and maximum parts are in the longitudinal direction of the steel material to be inspected. When it becomes a bipolar shape that is antisymmetric about the orthogonal direction axis, and a unimodal shape that is symmetric about the longitudinal axis in the orthogonal direction (n is a natural number),
Each of these values is characterized in that the value is preset to indicate that the intersection of the longitudinal axis and the orthogonal axis of the steel material to be inspected is a damaged portion of the steel material to be inspected.

The nondestructive testing device of the eighth invention of the present application magnetizes the steel material to be inspected with a magnet from the outside of the concrete body in which the steel material to be inspected is buried, and then measures the magnetic flux density of the concrete body with a magnetic sensor. A non-destructive testing device for detecting the presence and/or position of a damaged part in the steel material to be inspected,
A magnetizing unit including a magnet that magnetizes the steel material to be inspected along its longitudinal direction by or without moving the magnetized surface as appropriate after arranging it close to the surface of the concrete body;
After arranging a magnetic sensor unit having a plurality of magnetic sensors arranged in a row close to the surface of the concrete body with the direction in which the magnetic sensors are arranged substantially perpendicular to the longitudinal direction of the steel material to be inspected, a magnetic flux density measurement unit that measures the magnetic flux density of the steel material to be inspected by or without moving the steel material in the longitudinal direction;
A raw contour map generation process that generates a contour map of magnetic flux density based on the magnetic flux density measured by the magnetic flux density measurement unit, and a flattened contour map by subtracting a linear change in the longitudinal direction of the magnetic flux density from the raw contour map. a smoothing process to obtain a smoothed contour map, a smoothing process to obtain a smoothed contour map by smoothing the flattened contour map in the longitudinal direction, and a first-order or multiple-order differential in the longitudinal direction for the smoothed contour map. At least the above-mentioned raw contour map generation process and the above-mentioned flattening process. or at least the above raw contour map generation process, the flattening process and the smoothing process, or at least the above raw contour map generation process and the differentiation process, or at least the above raw contour map generation process and a contour map processing unit that performs the flattening process and the integration process;
Compare any one of the flattened contour map, smoothed contour map, differential contour map, and integral contour map with a predetermined criterion value to determine the presence and/or location of damaged parts in the steel material to be inspected. and a determination unit to
The above judgment standard value is
The direction of the magnetic flux within the steel material to be inspected is the longitudinal direction of the steel material to be inspected, and the magnetic flux density component in a direction substantially orthogonal to the surface of the concrete body, or its differential or integral in the longitudinal direction, is substantially orthogonal to the surface of the concrete body. When drawing a contour map with the direction away from the steel material being inspected as positive and the opposite direction as negative,
In the determination using the above differential contour map, the minimum part of the contour line is the first or (1+4n) order of odd-order differentiation, and the maximum part of the contour line is the third-order or (3+4n) order of odd-order differentiation. When each of the above-mentioned steel materials to be inspected has a symmetrical single peak shape in the longitudinal direction with respect to the orthogonal direction axis and in the orthogonal direction with respect to the longitudinal direction axis (n is a natural number),
In addition, in the judgment using the above integral contour map, the maximum part of the contour line in the first-order integral is symmetrical in the longitudinal direction of the steel material to be inspected with respect to the orthogonal direction axis, and in the orthogonal direction with respect to the longitudinal direction axis. When it is unimodal,
Each of these values is preset to indicate that the intersection of the longitudinal axis and the orthogonal axis of the steel material to be inspected is a damaged portion of the steel material to be inspected,
Or, the above judgment standard value is
The direction of the magnetic flux within the steel material to be inspected is a direction opposite to the longitudinal direction of the steel material to be inspected, and the magnetic flux density component in a direction approximately perpendicular to the surface of the concrete body, or its differential or integral in the longitudinal direction is the surface of the concrete body. When drawing a contour map with the direction substantially perpendicular to the steel material and moving away from the steel material to be inspected as positive and the opposite direction as negative,
In the judgment using the above differential contour map, the maximum part of the contour line is the first or (1+4n) order of the odd order differentiation, and the minimum part of the contour line is the third order or (3+4n) order of the odd order differentiation. When each of the above-mentioned steel materials to be inspected has a symmetrical single peak shape in the longitudinal direction with respect to the orthogonal direction axis and in the orthogonal direction with respect to the longitudinal direction axis (n is a natural number),
In addition, in the judgment using the above integral contour map, the minimum part of the contour line in the first-order integral is symmetrical in the longitudinal direction of the steel material to be inspected with respect to the orthogonal direction axis, and in the orthogonal direction with respect to the longitudinal direction axis. When it is unimodal,
Each of these values is characterized in that the value is preset to indicate that the intersection of the longitudinal axis and the orthogonal axis of the steel material to be inspected is a damaged portion of the steel material to be inspected.

The non-destructive testing device according to the ninth invention of the present application magnetizes the steel material to be inspected with a magnet from the outside of the concrete body in which the steel material to be inspected is buried, and then measures the magnetic flux density of the concrete body with a magnetic sensor. A non-destructive testing device for detecting the presence and/or position of a damaged part in the steel material to be inspected,
A magnetizing unit including a magnet that magnetizes the steel material to be inspected along its longitudinal direction by or without moving the magnetized surface as appropriate after arranging it close to the surface of the concrete body;
At least one magnetic sensor unit including a plurality of magnetic sensors arranged in a row and another magnetic sensor unit are arranged in such a manner that the direction in which each magnetic sensor is arranged is substantially perpendicular to the longitudinal direction of the steel material to be inspected, and After fixing the relative positions of both magnetic sensor units so as to move away from the surface of the concrete object sequentially, the magnetic flux density of the steel material to be inspected can be determined by moving or not moving in the longitudinal direction of the steel material to be inspected. a magnetic flux density measurement unit that measures the
a first processing unit that generates respective raw contour maps of magnetic flux density based on magnetic flux densities respectively measured by the first magnetic sensor unit and the other magnetic sensor unit in the magnetic flux density measuring unit; and each of the raw contour maps of the magnetic flux density. A flattening process is performed to obtain a flattened contour map by subtracting a linear change in the magnetic flux density in the longitudinal direction, and a smoothing process is performed to obtain a smoothed contour map by smoothing each of the flattened contour maps in the longitudinal direction. a second processing unit that performs a processing and synthesizes each of the smoothed contour maps by calculation based on the buried depth of the steel material to be inspected from the surface of the concrete body to obtain a composite smoothed contour map; The above smoothed contour maps are differentiated by one or more floors in the longitudinal direction to obtain differential contour maps, and each differential contour map is calculated based on the burial depth. A third processing unit performs integration processing to obtain integral contour maps by performing first-order integration in the longitudinal direction on each of the smoothed contour maps, and calculates the buried depth. A fourth processing unit that combines the respective integral contour maps based on the calculation to obtain a composite integral contour diagram, comprises at least the first processing unit and the second processing unit, or includes at least the first processing unit and the second processing unit, or a contour map processing section comprising a first processing section and the third processing section, or at least the first processing section and the fourth processing section;
Judgment to determine the presence or absence and/or position of damaged parts in the steel material to be inspected by comparing any of the composite smoothed contour map, composite differential contour map, and composite integral contour map with a predetermined criterion value. Equipped with a
The above judgment standard value is
The direction of the magnetic flux within the steel material to be inspected is the longitudinal direction of the steel material to be inspected, and the magnetic flux density component in a direction substantially orthogonal to the surface of the concrete body, or its differential or integral in the longitudinal direction, is substantially orthogonal to the surface of the concrete body. When drawing a contour map with the direction away from the steel material being inspected as positive and the opposite direction as negative,
In the determination using the composite smoothed contour map, the maximum and minimum parts of the contour lines appear sequentially in the longitudinal direction of the steel to be inspected, and the maximum and minimum parts are orthogonal to each other in the longitudinal direction of the steel to be inspected. When it becomes a bipolar shape that is antisymmetric about the axis and a unimodal shape that is symmetric about the longitudinal axis in the orthogonal direction,
In the judgment using the above composite differential contour map, in the second order or (2+4n) order differential among the even-numbered differentials, the minimum and maximum parts of the contour line appear sequentially in the longitudinal direction of the steel material to be inspected, and the minimum part and When the maximum part has a bipolar shape that is antisymmetrical to the orthogonal direction axis in the longitudinal direction of the steel to be inspected, and a single peak shape that is symmetrical to the longitudinal direction in the orthogonal direction (n is a natural number),
Furthermore, in the 4th or (4+4n) order differential among the even-numbered differentiations, the maximum and minimum parts of the contour line appear sequentially in the longitudinal direction of the steel material to be inspected, and the maximum and minimum parts of the contour line appear in the longitudinal direction of the steel material to be inspected. When it becomes a bipolar shape that is antisymmetric about the orthogonal direction axis, and a unimodal shape that is symmetric about the longitudinal axis in the orthogonal direction (n is a natural number),
Each of these values is preset to indicate that the intersection of the longitudinal axis and the orthogonal axis of the steel material to be inspected is a damaged portion of the steel material to be inspected,
Or, the above judgment standard value is
The direction of the magnetic flux within the steel material to be inspected is a direction opposite to the longitudinal direction of the steel material to be inspected, and the magnetic flux density component in a direction approximately perpendicular to the surface of the concrete body, or its differential or integral in the longitudinal direction is the surface of the concrete body. When drawing a contour map with the direction substantially perpendicular to the steel material and moving away from the steel material to be inspected as positive and the opposite direction as negative,
In the judgment using the composite smoothed contour map, the minimum and maximum parts of the contour line appear sequentially in the longitudinal direction of the steel to be inspected, and the minimum and maximum parts are orthogonal to each other in the longitudinal direction of the steel to be inspected. When it becomes a bipolar shape that is antisymmetric about the axis and a unimodal shape that is symmetric about the longitudinal axis in the orthogonal direction,
In the judgment using the composite differential contour map, the maximum and minimum parts of the contour line appear sequentially in the longitudinal direction of the steel material to be inspected in the second order or (2+4n) order of the even-numbered differentiation, and When the minimum part has a bipolar shape that is antisymmetrical to the orthogonal direction axis in the longitudinal direction of the steel material to be inspected, and a unimodal shape that is symmetrical to the longitudinal direction in the orthogonal direction (n is a natural number),
Furthermore, in the 4th or (4+4n) order differential among the even-numbered differentiations, the minimum and maximum parts of the contour lines appear sequentially in the longitudinal direction of the steel material to be inspected, and the minimum and maximum parts are in the longitudinal direction of the steel material to be inspected. When it becomes a bipolar shape that is antisymmetric about the orthogonal direction axis, and a unimodal shape that is symmetric about the longitudinal axis in the orthogonal direction (n is a natural number),
Each of these values is characterized in that the value is preset to indicate that the intersection of the longitudinal axis and the orthogonal axis of the steel material to be inspected is a damaged portion of the steel material to be inspected.

A non-destructive testing device according to a tenth aspect of the present invention is configured to magnetize the steel material to be inspected from outside of the concrete body in which the steel material to be inspected is buried using a magnet, and then measure the magnetic flux density of the concrete body using a magnetic sensor. and a non-destructive testing device for detecting the presence or absence and/or position of a damaged part in the above-mentioned steel material to be inspected,
A magnetizing unit including a magnet that magnetizes the steel material to be inspected along its longitudinal direction by or without moving the magnetized surface as appropriate after arranging it close to the surface of the concrete body;
At least one magnetic sensor unit including a plurality of magnetic sensors arranged in a row and another magnetic sensor unit are arranged in such a manner that the direction in which each magnetic sensor is arranged is substantially perpendicular to the longitudinal direction of the steel material to be inspected, and After fixing the relative positions of both magnetic sensor units so as to move away from the surface of the concrete object sequentially, the magnetic flux density of the steel material to be inspected can be determined by moving or not moving in the longitudinal direction of the steel material to be inspected. a magnetic flux density measurement unit that measures the
a first processing unit that generates respective raw contour maps of magnetic flux density based on magnetic flux densities respectively measured by the first magnetic sensor unit and the other magnetic sensor unit in the magnetic flux density measuring unit; and each of the raw contour maps of the magnetic flux density. A flattening process is performed to obtain a flattened contour map by subtracting a linear change in the magnetic flux density in the longitudinal direction, and a smoothing process is performed to obtain a smoothed contour map by smoothing each of the flattened contour maps in the longitudinal direction. a second processing unit that performs a processing and synthesizes each of the smoothed contour maps by calculation based on the buried depth of the steel material to be inspected from the surface of the concrete body to obtain a composite smoothed contour map; The above smoothed contour maps are differentiated by one or more floors in the longitudinal direction to obtain differential contour maps, and each differential contour map is calculated based on the burial depth. A third processing unit performs integration processing to obtain integral contour maps by performing first-order integration in the longitudinal direction on each of the smoothed contour maps, and calculates the buried depth. A fourth processing unit that combines the respective integral contour maps based on the calculation to obtain a composite integral contour diagram, comprises at least the first processing unit and the second processing unit, or includes at least the first processing unit and the second processing unit, or a contour map processing section comprising a first processing section and the third processing section, or at least the first processing section and the fourth processing section;
Judgment to determine the presence or absence and/or position of damaged parts in the steel material to be inspected by comparing any of the composite smoothed contour map, composite differential contour map, and composite integral contour map with a predetermined criterion value. Equipped with a
The above judgment standard value is
The direction of the magnetic flux within the steel material to be inspected is the longitudinal direction of the steel material to be inspected, and the magnetic flux density component in a direction substantially orthogonal to the surface of the concrete body, or its differential or integral in the longitudinal direction, is substantially orthogonal to the surface of the concrete body. When drawing a contour map with the direction away from the steel material being inspected as positive and the opposite direction as negative,
In the judgment using the above synthetic differential contour map, the minimum part of the contour line is the first or (1+4n) order of the odd-order differentiation, and the maximum part of the contour line is the third-order or (3+4n) order of the odd-order differentiation. , when the longitudinal direction of the steel material to be inspected has a symmetrical single peak shape with respect to the orthogonal direction axis, and the orthogonal direction with respect to the longitudinal direction axis (n is a natural number),
In addition, in the judgment using the above composite integral contour map, the maximum part of the contour line in the first-order integral is symmetrical in the longitudinal direction of the steel material to be inspected with respect to the orthogonal direction axis, and in the orthogonal direction with respect to the longitudinal direction axis. When the shape is unimodal,
Each of these values is preset to indicate that the intersection of the longitudinal axis and the orthogonal axis of the steel material to be inspected is a damaged portion of the steel material to be inspected,
Or, the above judgment standard value is
The direction of the magnetic flux within the steel material to be inspected is a direction opposite to the longitudinal direction of the steel material to be inspected, and the magnetic flux density component in a direction approximately perpendicular to the surface of the concrete body, or its differential or integral in the longitudinal direction is the surface of the concrete body. When drawing a contour map with the direction substantially perpendicular to the steel material and moving away from the steel material to be inspected as positive and the opposite direction as negative,
In the judgment using the above synthetic differential contour map, the maximum part of the contour line is the first or (1+4n) order of the odd-order differentiation, and the minimum part of the contour line is the minimum part of the contour line for the third or (3+4n) order of the odd-order differentiation. , when the longitudinal direction of the steel material to be inspected has a symmetrical single peak shape with respect to the orthogonal direction axis, and the orthogonal direction with respect to the longitudinal direction axis (n is a natural number),
In addition, in the judgment using the above synthetic integral contour map, the minimum part of the contour line in the first-order integral is symmetrical in the longitudinal direction of the steel material to be inspected with respect to the orthogonal direction axis, and in the orthogonal direction with respect to the longitudinal direction axis. When the shape is unimodal,
Each of these values is characterized in that the value is preset to indicate that the intersection of the longitudinal axis and the orthogonal axis of the steel material to be inspected is a damaged portion of the steel material to be inspected.

A non-destructive testing device according to an eleventh invention of the present application is a non-destructive testing device according to the ninth or tenth invention, which includes:
The above-mentioned burial depth is shown in each raw contour map generated based on the magnetic flux densities respectively measured by the one magnetic sensor unit and the other magnetic sensor unit in the magnetic flux density measurement unit, and each raw contour map described above. Each smoothed contour map obtained by longitudinally smoothing each flattened contour map obtained by subtracting the longitudinal linear change in magnetic flux density, and each smoothed contour map obtained by longitudinally smoothing each of the above smoothed contour maps. At least one contour map of each differential contour map obtained by first- order or multiple-order differentiation and each integral contour map obtained by performing first-order integration in the longitudinal direction on each of the smoothed contour maps. It is characterized by being calculated by calculation based on the

A non-destructive testing device according to a twelfth invention of the present application is a non-destructive testing device according to the seventh, eighth, ninth, tenth or eleventh invention, comprising:
The determination unit verifies the accuracy of the determination result based on the comparison between the raw contour map, flattened contour map, smoothed contour map, differential contour map, and integral contour map and the determination reference value, and again If it is determined that it is necessary to make a judgment, the existence and/or location of damaged parts of the steel material to be inspected is determined by comparing the above judgment standard values with another contour map different from the contour map used for the previous judgment. It is characterized by a configuration that re-determines the

(a) Non-destructive testing methods according to the first and second inventions of the present application and non-destructive testing apparatuses according to the seventh and eighth inventions Non-destructive testing methods and seventh inventions according to the first and second inventions of the present application According to the non-destructive testing device according to the eighth invention, the steel material to be inspected is magnetized from the outside of the concrete body in which the steel material to be inspected is buried (magnetization step), and then the steel material to be inspected is magnetized by the magnetic sensor. (magnetic flux density measurement process), and further, among the raw contour map, flattened contour map, smoothed contour map, differential contour map, and integral contour map, at least the above raw contour map and flattened contour map, Alternatively, at least the above raw contour map, flattened contour map, and smoothed contour map, or at least the above raw contour map and differential contour map, or at least the above raw contour map, flattened contour map, and integral contour map are used. Figure processing process), the peak characteristics of magnetic flux density characteristic of damage to the steel material to be inspected in these contour maps (i.e., the order in which the maximum and minimum parts of magnetic flux density appear, the symmetry of the maximum and minimum parts, etc.) This is used as an index for determining the presence or absence of damage, and is compared with a preset determination reference value to determine the presence and/or position of a damaged portion in the steel material to be inspected (determination step). That is, in the case of damage to the steel material to be inspected, attention is paid to the phenomenon that the maximum and minimum parts of the contour map are symmetrical or antisymmetric, and this is used as a criterion for determining damage.

Therefore, for example, as in the past, the state of the rate of change in magnetic flux density (differential value of magnetic flux density) can be compared with data obtained by mock-up measurements, etc., to qualitatively determine the fracture (damage) of reinforcing bars (steel material to be inspected). It is possible to judge the presence or absence of damage more accurately and accurately than those that inspect the presence or absence of damage, and there is no need to learn from large amounts of data, which makes it easier to inspect the presence or absence and/or location of damaged parts. It can be carried out simply and quickly, and as a synergistic effect, it is possible to reduce the cost of inspecting the presence and/or position of damaged parts in the steel material to be inspected.

In addition, since the process of determining the presence and/or location of damaged parts in the steel material being inspected is clear, even cases where there is no learning database can be handled extremely easily and non-destructively. The versatility of inspection methods and non-destructive inspection equipment is improved.

Furthermore, the above-mentioned flattened contour map, smoothed contour map, differential contour map, and integral contour map can all be used to determine the presence or absence and/or location of damaged parts in the steel material to be inspected, and any of the contour maps can be used to It is up to the inspection subject to make these decisions based on the information provided, and the diversification of non-destructive inspection methods will be promoted.

(b) Non-destructive testing methods according to the third and fourth inventions of the present application and non-destructive testing apparatuses according to the ninth and tenth inventions Non-destructive testing methods and ninth inventions according to the third and fourth inventions of the present application In the non-destructive testing device according to the tenth invention, the steel material to be tested is magnetized from the outside of the concrete body in which the steel material to be tested is buried (magnetization step), and then a plurality of sensors are arranged in a row. at least one magnetic sensor unit and another magnetic sensor unit are arranged so as to move away from the surface of the concrete body in sequence,
A first processing step of obtaining a raw contour map based on the magnetic flux densities respectively measured by the one magnetic sensor unit and the other magnetic sensor unit;
Flattening each raw contour map above, performing smoothing processing on each flattened contour map to obtain a smoothed contour map, and calculate each smoothed contour map based on the burial depth. a second processing step of synthesizing to obtain a composite smoothed contour map;
A third processing step of performing differential processing on each of the smoothed contour maps to obtain a differential contour map, and composing the respective differential contour maps by calculation based on the burial depth to obtain a composite differential contour map; ,
A fourth processing step in which each of the smoothed contour maps is subjected to an integral process to obtain an integral contour map, and each of the integral contour maps is combined by calculation based on the burial depth to obtain a composite integral contour map. home,
Performing at least the first treatment step and the second treatment step, or at least the first treatment step and the third treatment step, or at least the first treatment step and the fourth treatment step. (contour map processing process),
The existence and/or location of damaged parts of the steel material to be inspected is determined by comparing any of these composite smoothed contour maps, composite differential contour diagrams, and composite integral contour diagrams with preset judgment reference values ( (judgment process).

Here, in the composite smoothed contour map, composite differential contour map, and composite integral contour map, noise components due to other reinforcing bars placed in the vicinity of the above-mentioned steel material to be inspected are removed, and the influence of the above-mentioned steel material to be inspected is emphasized. This results in a clearer contour map.

For this reason, comparison with the above-mentioned criterion values is easier than, for example, when determining the presence or absence and/or location of a damaged part based on a smoothed contour map or differential contour map before composition processing. In addition, the method is accurate, and the accuracy of determining the presence/absence and/or position of a damaged portion of the steel material to be inspected is improved, which is extremely useful in practice.

In addition to the above effects,
(b) For example, as in the past, the state of the change rate of magnetic flux density (differential value of magnetic flux density) is compared with the data obtained by mock-up measurements, etc., and the fracture (damage ), it is possible to judge the presence or absence of damage more accurately and accurately, and there is no need to learn from large amounts of data, making it easier and faster to inspect for the presence or absence of damage. As a synergistic effect, it is possible to reduce the cost of inspecting the presence and/or location of damaged parts in the steel material to be inspected.

(b) Furthermore, since the process of determining the presence or absence and/or location of damaged parts in the steel material being inspected is clear, even cases where there is no learning database can be handled extremely easily. , the versatility of non-destructive testing methods and non-destructive testing equipment is improved;
This effect can also be obtained.

(c) Non-destructive testing method according to the fifth invention of the present application and non-destructive testing apparatus according to the eleventh invention In the non-destructive testing method according to the fifth invention of the present application and the non-destructive testing apparatus according to the eleventh invention, In addition to the effects described in (b) above, the following unique effects can be obtained. That is, in these inventions, the buried depth of the steel material to be inspected from the surface of the concrete body is determined by at least one of the raw contour maps , each smoothed contour map, each differential contour map, and each integral contour map. Since it is calculated by calculation based on When obtaining a smoothed contour map etc., the burial depth obtained here can be used, and the presence and/or position of damaged parts in the steel material to be inspected can be more easily and accurately inspected.

(d) Non-destructive testing method according to the sixth invention of the present application and non-destructive testing apparatus according to the twelfth invention In the non-destructive testing method according to the sixth invention of the present application and the non-destructive testing apparatus according to the twelfth invention, In addition to the above (a), (b) or (c), the following unique effects can be obtained. That is, in these inventions, the determination step or determination section compares any one of the raw contour map, flattened contour map, smoothed contour map, differential contour map, and integral contour map with the determination reference value. Verify the accuracy of the judgment results based on the above, and if it is determined that a second judgment is necessary, perform the above test by comparing the above judgment standard values with another contour map different from the one used for the previous judgment. Since the existence and/or location of damaged parts of the target steel material is re-determined, it is possible to quickly obtain more accurate determinations, improving the reliability of non-destructive testing methods and non-destructive testing equipment. .

1 is a functional block diagram of a non-destructive testing method and testing device according to a first embodiment of the present invention; FIG. It is a typical explanatory view of the magnetic flux density measurement form in the above-mentioned non-destructive inspection method and inspection device. FIG. 3 is a schematic explanatory diagram of leakage magnetism from magnetized reinforcing bars at a site where there is a damaged part. FIG. 3 is a schematic explanatory diagram of leakage magnetism from magnetized reinforcing bars in a region where there is no damaged part. It is a raw contour map acquired based on the magnetic flux density measured by the magnetic sensor. It is a flattened contour map obtained by flattening the raw contour map. It is a smoothed contour map obtained by subjecting the flattened contour map to smoothing processing. It is a first-order differential contour map obtained by performing first-order differential processing on the smoothed contour map. It is a second-order differential contour map obtained by performing second-order differential processing on the smoothed contour map. It is a first-order integral contour map obtained by performing first-order integral processing on the smoothed contour map. FIG. 2 is a second-order differential contour map for a region without a damaged part. FIG. 2 is a functional block diagram of a non-destructive testing method and testing device according to a second embodiment of the present invention. It is a typical explanatory view of the magnetic flux density measurement form in the above-mentioned non-destructive inspection method and inspection device. FIG. 2 is a smoothed contour map obtained based on magnetic flux density measured by a magnetic sensor placed at a height close to the surface of a concrete body. FIG. 7 is another smoothed contour map obtained based on the magnetic flux density measured by another magnetic sensor placed at a height far from the surface of the concrete body. It is a composite smoothed contour map obtained by combining one smoothed contour map and another smoothed contour map by calculation. 1 is a first-order differential contour map obtained by performing first-order differential processing on a first-order smoothed contour map. It is another first-order differential contour map obtained by performing first-order differential processing on another smoothed contour map. This is a composite first-order differential contour map obtained by composing the first-order differential contour map and another first-order differential contour map by calculation. It is a second-order differential contour map obtained by subjecting the first smoothed contour map to second-order differential processing. It is another second-order differential contour map obtained by performing second-order differential processing on the above-mentioned other smoothed contour map. This is a composite second-order differential contour map obtained by composing the first second-order differential contour map and another second-order differential contour map by calculation. FIG. 3 is a first-order integral contour map obtained by performing first-order integral processing on the first flattened contour map. It is another first-order integral contour map obtained by performing first-order integral processing on the above-mentioned other flattened contour map. This is a composite first-order integral contour map obtained by composing the first-order integral contour map and another first-order integral contour map by calculation. FIG. 3 is a functional block diagram of a non-destructive testing method and testing device according to a third embodiment of the present invention. FIG. 3 is an explanatory diagram showing the relationship between a contour diagram and a magnetic flux density waveform diagram.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A non-destructive testing method and testing device according to the present invention will be described below based on embodiments.

A: Explanation of the basic idea First, the basic idea of the non-destructive testing method and non-destructive testing device according to the present invention will be explained, and then a specific explanation will be given based on the embodiments.

A-1: Regarding the steel material to be inspected Here, we assume that the steel material to be inspected to which the non-destructive testing method and equipment are applied is the reinforcing bar 2 buried in the concrete body 1. It is possible to inspect whether or not there is a damaged part (specifically, a "broken part") in the longitudinal direction of the concrete body 1 based on a contour map obtained from the outside of the concrete body 1.

A-2: Basic concept for inspecting damaged parts of reinforcing bars 2 (a) Regarding magnetization of reinforcing bars 2 Magnetizing the reinforcing bars 2 buried in the concrete body 1 is performed using a conventionally well-known process (for example, Patent Document 1 (see). That is, as shown in FIG. 1, after the magnet 8 is placed close to the surface 1a of the concrete body 1, it is magnetized along the longitudinal direction of the reinforcing bar 2 by moving it appropriately or without moving it. Through this magnetization operation, the reinforcing bar 2 is magnetized under the influence of the magnetism of the magnet 8, and magnetic flux is generated along the longitudinal direction of the reinforcing bar 2 in a direction from the S pole side to the N pole side (Fig. (See 3). After magnetization, the magnet 8 is removed from the concrete body surface 1a.

The magnet 8 is a rectangular parallelepiped permanent magnet made of a rare earth metal such as Nd, but is not limited to this. For example, it may be an electromagnet instead of a permanent magnet, and the shape is not limited to a rectangular parallelepiped. It may be letter-shaped or U-shaped.

(b) Measurement of residual magnetic flux density using a magnetic sensor Magnetism leaking to the outside from the reinforcing bars 2 can be measured by placing a magnetic sensor 4 close to the surface 1a of the concrete body 1, as shown in FIGS. 3 and 4. By moving the reinforcing bar 2 in the longitudinal direction, an electric signal corresponding to the magnitude thereof is obtained. The measured value of the magnetic flux density measured by the magnetic sensor 4 is subjected to contour mapping processing in a contour map processing unit 20 (see FIG. 1), which will be described later, to form a contour map (see FIGS. 5 to 10).

(b-1) Measurement of magnetic flux density in a part with a damaged part FIG. 3 shows the state of residual magnetism in the reinforcing bar 2 with a damaged part 2A. In this damaged portion 2A, one end 2B side becomes a N pole, the other end 2C opposite thereto becomes an S pole, and the magnetic flux in the reinforcing bar 2 is interrupted at this damaged portion 2A. Then, on the one end 2B side of the reinforcing bar 2, a line of magnetic force 101b is generated from the N pole near the damaged part 2A toward the rear side (left side in the figure), and this causes the above-mentioned damage to the one end 2B side. A magnetic flux 102 is generated in the direction toward the portion 2A. Further, on the other end 2C side, a portion close to the damaged portion 2A becomes an S pole, and a magnetic flux 103 in a direction away from the damaged portion 2A is generated on the far 2C side. Furthermore, in the damaged portion 2A, lines of magnetic force 101a are generated that go from the north pole on one end 2B side to the south pole on the other end 2C side.

Furthermore, as shown in FIG. 3, on the one end 2B side, the magnetic flux 106 directed upward in the Z-axis direction (direction perpendicular to the surface of the concrete body 1) is applied to the north pole part, and the magnetic flux 106 is directed upward to the south pole part. A magnetic flux 104 is generated downward in the Z-axis direction. Further, on the other end 2C side, a magnetic flux 105 directed upward in the Z-axis direction is generated at the N-pole portion, and a magnetic flux 107 directed downward in the Z-axis direction is generated at the S-pole portion.

The magnetic flux density of the reinforcing bar 2 with this damaged part 2A was measured, and the Z-axis direction component is shown as a contour diagram (raw contour diagram) in relation to the measurement position in the longitudinal direction of the reinforcing bar 2. It is a raw contour map shown in FIG. Furthermore, a flattened contour map obtained by flattening this raw contour map is shown in FIG. 6, a smoothed contour map obtained by smoothing this flattened contour map is shown in FIG. Figure 8 shows a first-order differential contour map obtained by performing first-order differential processing, and Fig. 9 shows a second-order differential contour map obtained by performing second-order differential processing on the above-mentioned smoothed contour map. FIG. 10 shows first-order integral contour maps obtained by performing the integral processing.

(b-2) Measurement of magnetic flux density in a portion where a magnetized end exists FIG. 4 shows the state of residual magnetic flux in the reinforcing bar 2 where there is no damaged part but where a magnetized end exists. In this portion, the magnetic flux 108 in the direction from the south pole side to the north pole side of the reinforcing bar 2 is not interrupted on the way. In this case, a magnetic flux 111 directed upward in the Z-axis direction is produced in the N-pole region, and a magnetic flux 112 directed downward in the Z-axis direction is produced in the S-pole region. This magnetic flux density was measured and its Z-axis direction component was shown as a contour diagram (raw contour diagram) in relation to the measurement position in the longitudinal direction of the reinforcing bar 2 as shown in FIG. 11. It is.

(c) Relationship between the raw contour diagram and the magnetic flux density waveform Figure 27 schematically shows the relationship between the contour diagram and the magnetic flux density waveform. (For example, the contour diagram in the smoothed waveform (see FIG. 7)) is shown in Figure (b) when the magnetic flux density waveform is unimodal (for example, the contour diagram in the first-order differential magnetic flux density waveform (see Figure 7)). (See FIG. 8).

In the same figure (a), when the reinforcing steel is magnetized in the same direction (positive direction) as the longitudinal direction and the direction of magnetic flux is positive, the magnetic flux density waveform changes from "maximum part → minimum part" as shown by curve L1. '', and the maximum and minimum parts in this magnetic flux density waveform correspond to the maximum and minimum parts located on both sides of the Y-direction axis n in the contour map (p), respectively.

On the other hand, when the reinforcing steel is magnetized in the direction opposite to the longitudinal direction (opposite direction) and the direction of magnetic flux is reversed, the magnetic flux density waveform shifts from "minimum part to maximum part" as shown by curve L2. The "minimum part" and "maximum part" in the magnetic flux density waveform are the "minimum part" and "maximum part" located on both sides of the Y-direction axis n in the contour map (p). ” (shown in parentheses).

In the above contour map (p), the "maximum part" and "minimum part" (or "minimum part" and "maximum part") are opposite to the Y-direction axis n, which is perpendicular to the longitudinal direction of the reinforcing steel. It is symmetrical with respect to the X-direction axis m in the longitudinal direction of the reinforcing bar.

On the other hand, in the same figure (b), when the direction of magnetic flux is the same direction as the longitudinal direction of the reinforcing steel (positive direction), the magnetic flux density waveform becomes a single peak shape with a "minimum part" as shown by curve L3. The "minimum part" in the magnetic flux density waveform corresponds to the "minimum part" that is symmetrical in both the X direction axis m and the Y direction axis n in the contour map (q).

On the contrary, when the direction of magnetic flux is opposite to the longitudinal direction of the reinforcing steel (opposite direction), the magnetic flux density waveform becomes a single peak with a "maximum part" as shown by curve L4, and this magnetic flux density waveform The "maximum part" corresponds to the "maximum part" (shown in parentheses) that is symmetrical in both the X-direction axis m and the Y-direction axis n in the contour map (q).

As mentioned above, the smoothed contour map and the first-order differential contour map have their own unique shape, and depending on the relationship between the direction of magnetic flux with respect to the longitudinal direction of the reinforcing steel, even if they are the same contour map, The appearance order of the maximum and minimum parts is different, and even if the contour map is the same, the shape of the contour map differs when there is a damaged part in the reinforcing bar and when there is a magnetic flux edge instead of the damaged part. is completely different.

This situation also applies to other contour maps, such as the raw contour map (see Figure 5), the flattened contour map (see Figure 6), and the integral contour map (see Figure 10), as described below. It is. This can be determined by observing the contour map and comparing it with the standard line shape in each contour map (described later as "judgment reference value") to determine the presence or absence and/or location of damaged parts in the reinforcing bars 2. This means that the non-destructive testing method and non-destructive testing device according to the present invention are based on these findings.

B: First Embodiment FIG. 1 shows a functional block diagram of a non-destructive testing apparatus Z (including a non-destructive testing method) according to a first embodiment of the present invention. This non-destructive inspection device Z is for inspecting the existence and position of damaged parts of reinforcing bars 2 (inspection target steel materials 2) buried in a concrete body 1 from the outside without destroying the concrete body 1. More specifically, the reinforcing bars 2 are magnetized, the residual magnetic flux thereof is measured from outside the concrete body 1 using a magnetic sensor to obtain a magnetic flux density waveform, and a contour map is further obtained based on this magnetic flux density waveform. The existence and position of damaged parts in the reinforcing bars 2 is then inspected from the linear characteristics of this contour map. Hereinafter, the contents of the non-destructive inspection apparatus Z will be specifically explained, although there are some parts that overlap with those already described.

"Non-destructive inspection device Z"
As shown in FIG. 1, the non-destructive testing apparatus Z is configured to include an apparatus main body Za and a magnetized section 41, which will be described below. Further, the apparatus main body Za includes a magnetic flux density measurement section 10, a contour map processing section 20, a determination section 30, and a display section 40. Note that these devices do not necessarily need to be housed in one housing, but may be independent devices and connected by wired or wireless communication lines.

"Magnetized part 41"
The magnetized section 41 includes a magnet 8 . By placing this magnet 8 close to the surface 1a side of the concrete body 1 in which the reinforcing bars 2 as prestressing reinforcing bars and the cross reinforcing bars 3 substantially orthogonal to the reinforcing bars 2 are buried, or by moving the magnet 8 as appropriate. The reinforcing bars 2 are magnetized along the longitudinal direction without being After magnetization, the magnet 8 is removed from the concrete body surface 1a. Note that the function of the magnetizing section 41 corresponds to the "magnetizing step 48" in the non-destructive testing method.

"Magnetic flux density measurement section 10"
As shown in FIGS. 1 and 2, the magnetic flux density measurement unit 10 is a magnetic flux density measuring unit that integrally incorporates a plurality of magnetic sensors 4 (seven in this embodiment) and a distance sensor 7 arranged in a row at predetermined intervals. A sensor unit 5 is arranged close to the surface 1a of the concrete body 1 with the direction in which the magnetic sensors are arranged substantially perpendicular to the longitudinal direction of the steel material to be inspected, and the sensor unit 5 measures the residual magnetic flux of the reinforcing bar 2. Generate a magnetic flux density waveform.

Here, the reason why the magnetic sensor unit 5 is configured to include a plurality of the magnetic sensors 4 is to scan a wide range including the surrounding area of the reinforcing bars 2 at one time to increase work efficiency. Instead of such a configuration, for example, a single magnetic sensor 4 may be used and scanning in the longitudinal direction may be repeated while moving it by a predetermined width in a direction perpendicular to the longitudinal direction of the reinforcing bar 2 (Y direction).

The magnetism leaking to the outside from the reinforcing bar 2 is acquired by each magnetic sensor 4 of the magnetic sensor unit 5 as an electric signal according to its magnitude. The measured value of the magnetic flux density measured by the magnetic sensor 4 is subjected to contour plotting processing in a contour plot processing unit 20, which will be described later, to form a contour plot (see FIGS. 5 to 10). Note that the function of the magnetic flux density measuring section 10 corresponds to the "magnetic flux density measuring step 45" in the non-destructive testing method.

“Contour map processing unit 20”
The contour map processing section 20 includes a raw line diagram generation section 21 , a flattening processing section 22 , a smoothing processing section 23 , a differential processing section 24 , and an integral processing section 25 .

The raw line diagram generating unit 21 converts the Z-axis direction component of the measured value of magnetic flux density obtained by the magnetic flux density measuring unit 10 into a contour diagram in relation to the measurement position in the longitudinal direction of the reinforcing bar 2, and converts this into a contour map. , which is expressed as a raw contour map as shown in FIG. The raw contour diagram in FIG. 5 corresponds to the Z-axis direction component of the bipolar magnetic flux density waveform, and the maximum and minimum portions located on both sides of the Y-direction axis n are both located at the reinforcing bar 2. There is a large decrease in the longitudinal direction (that is, the direction along the X-direction axis m), making it relatively difficult to accurately recognize the positions of the maximum and minimum parts. Therefore, in this embodiment, this raw contour map is used as the basis for the flattening process, smoothing process, differential process, and integral process described below. It is not used as a document.

The flattening processing section 22 performs a flattening process of subtracting a linear change in the longitudinal direction of magnetic flux density from the raw contour map to obtain a flattened contour map, and this flattened contour map is shown in FIG. It shows. This flattened contour map corresponds to the Z-axis direction component of the bipolar magnetic flux density waveform, and when the direction of the magnetic flux inside the reinforcing bar 2 is the longitudinal direction (X-axis direction), the maximum part and The minimum parts appear in the order of "maximum part → minimum part", and the maximum part and the minimum part are antisymmetric with respect to the Y direction axis n, and the maximum part and the minimum part are both together with respect to the X direction axis m. It is symmetrical (see Table 1). It is estimated that the intersection of the X-direction axis m and the Y-direction axis n is the damaged part of the reinforcing bar 2. Therefore, this flattened contour map can be used in the determining section 30, which will be described later, to determine the presence or absence and position of a damaged portion of the reinforcing bar 2.

The smoothing processing section 23 performs a smoothing process to smooth the flattened contour map in the longitudinal direction to obtain a smoothed contour map, and this smoothed contour map is shown in FIG. This smoothed contour map corresponds to the Z-axis direction component of the bipolar magnetic flux density waveform, and when the direction of the magnetic flux inside the reinforcing bar 2 is the longitudinal direction (X-axis direction), the maximum part and The minimum parts appear in the order of "maximum part→minimum part", and the maximum part and minimum part are antisymmetrical with respect to the Y-direction axis n, and the maximum part and the minimum part are respectively symmetrical with respect to the X-direction axis m. It is symmetrical (see Table 1). It is estimated that the intersection of the X-direction axis m and the Y-direction axis n is the damaged part of the reinforcing bar 2. Therefore, this flattened contour map can be used by the determination unit 30, which will be described later, to determine the presence or absence and position of damaged parts of the reinforcing bars 2.

The differential processing unit 24 performs first-order and multiple-order differential processing on the smoothed contour map in the longitudinal direction, and generates a first-order differential contour map and a multiple-order differential contour map (for example, a second-order differential contour map, a third-order differential contour map, The first-order differential contour map is shown in FIG. 8, and the second-order differential contour map is shown in FIG. 9.

The first-order differential contour diagram shown in FIG. 8 corresponds to the Z-axis direction component of the unimodal magnetic flux density waveform, and when the direction of the magnetic flux inside the reinforcing bar 2 is the longitudinal direction (X-axis direction). has a minimum part, and this minimum part is symmetrical in both the X direction axis m and the Y direction axis n (see Table 1). It is estimated that the intersection of the X-direction axis m and the Y-direction axis n is the damaged part of the reinforcing bar 2. Therefore, this first-order differential contour map can be used in the determining section 30, which will be described later, to determine the presence or absence and position of a damaged portion of the reinforcing bar 2.

The second-order differential contour diagram shown in FIG. 9 corresponds to the Z-axis direction component of the bipolar magnetic flux density waveform, and when the direction of the magnetic flux inside the reinforcing bar 2 is the longitudinal direction (X-axis direction), In this case, the maximum part and the minimum part appear in the order of "minimum part → maximum part", the minimum part and the maximum part are antisymmetric with respect to the Y direction axis n, and the minimum part and the maximum part appear in the X direction axis m. are symmetrical (see Table 1). It is estimated that the intersection of the X-direction axis m and the Y-direction axis n is the damaged part of the reinforcing bar 2. Therefore, this first-order differential contour map can be used in the determining section 30, which will be described later, to determine the presence or absence of a damaged portion of the reinforcing bar 2 and the damaged position.

Although not shown, the third-order differential contour map corresponds to the Z-axis direction component of the unimodal magnetic flux density waveform, and the direction of the magnetic flux within the reinforcing bar 2 is the longitudinal direction (X-axis direction). In this case, it has a maximum part, and this maximum part is symmetrical in both the X direction axis m and the Y direction axis n (see Table 1). It is estimated that the intersection of the X-direction axis m and the Y-direction axis n is the damaged part of the reinforcing bar 2. Therefore, this third-order differential contour map can be used in the determining section 30, which will be described later, to determine the presence or absence and position of a damaged portion of the reinforcing bar 2.

Although not shown, the fourth-order differential contour map corresponds to the Z-axis direction component of the bipolar magnetic flux density waveform, and when the direction of the magnetic flux within the reinforcing bar 2 is the longitudinal direction (X-axis direction). , the maximum part and the minimum part appear in the order of "maximum part → minimum part", and the maximum part and the minimum part are both antisymmetric with respect to the Y direction axis n, and the maximum part appears with respect to the X direction axis m. and the minimum part are symmetrical (see Table 1). It is estimated that the intersection of the X-direction axis m and the Y-direction axis n is the damaged part of the reinforcing bar 2. Therefore, this flattened contour map can be used by the determining section 30, which will be described later, to determine the presence or absence and position of a damaged portion of the reinforcing bar 2.

In this way, the differential contour maps of odd-numbered orders are both unimodal, but as the rank changes, they change from unimodal (first-order differential contour) with a minimum to a maximum. The minimum and maximum parts alternately change to a unimodal shape (third-order differential contour map) with (see Table 1).

On the other hand, even-numbered differential contour maps are bipolar differential contour maps, but as the rank changes, the order in which the maximum and minimum parts appear changes from "minimum part to maximum part" (second-order differential contour map). (Differential contour map) changes from "maximum part to minimum part" (4th order differential contour map) (see Table 1).

Since this change characteristic remains unchanged, not only the first-order differential contour map and the second-order differential contour map, but also the higher-order differential contour maps are used in the determining section 30 (to be described later) to determine the damaged area of the reinforcing bar 2. It can be used to determine the presence and location of

“Integral processing unit 25”
The integral processing section 25 performs first-order integration in the longitudinal direction on the smoothed contour map to obtain a first-order integral contour map, and this first-order integral contour map is shown in FIG. If the direction of the magnetic flux within the reinforcing bar 2 is the longitudinal direction (X-axis direction), this first-order integral contour map becomes a contour map with a single-peak maximum part, and this maximum part is along the X-direction axis m. and the Y direction axis n (see Table 1). It is estimated that the intersection of the X-direction axis m and the Y-direction axis n is the damaged part of the reinforcing bar 2. Therefore, this first-order integral contour map can be used by the determination unit 30, which will be described later, to determine the presence or absence of a damaged portion of the reinforcing bar 2 and the location of the damage. Note that the function of the contour map processing section 20 corresponds to the "contour map processing step 46" in the non-destructive testing method.

“Judgment unit 30”
The determination unit 30 determines the presence or absence and position of the damaged portion of the reinforcing bars 2 based on the contour map acquired by the contour map processing unit 20, and includes a determination target selection unit 31 and a first determination processing unit 32. , a determination accuracy determining section 33 , and a second determination processing section 34 .

The determination target selection unit 31 selects the external visibility condition of the concrete body 1 from among the flattened contour map, smoothed contour map, differential contour map, and integral contour map acquired by the contour map processing unit 20. The most appropriate contour map is selected based on the buried state of the reinforcing bars 2, etc.

The first determination processing unit 32 compares the contour map selected by the determination target selection unit 31 with a preset determination reference value 42, and determines whether or not there is a damaged part of the reinforcing bar 2 according to the selected contour map. Determine location accuracy. If it is determined that the accuracy is at a predetermined level or higher, the selected contour map and the determination results of the existence and position of damaged parts of the reinforcing bars 2 are displayed on the display unit 40.

On the other hand, if the determination accuracy determination unit 33 determines that the accuracy level has not been reached to a sufficient level, the second determination processing unit 34 selects another contour map different from the previously selected contour map. , re-select this contour map and compare it with the above-mentioned judgment reference value 42 to re-judge the determination accuracy of the contour map, and display the contour map and the determination results of the presence/absence and position of damaged parts of reinforcing bars 2 on the display section. 40. Note that it is optional whether the determination accuracy in this contour map is re-determined only once or multiple times.

In addition, the above-mentioned judgment standard value 42 is used as a standard when inspecting the existence and position of damaged parts of reinforcing bars 2 using each of the above-mentioned contour maps, such as a flattened contour map, a smoothed contour map, a differential contour map and an integral contour map For each case, the settings are confirmed and set in advance by, for example, mock-up measurements.

Here, "Table 1" is shown which summarizes the processing methods of flattening processing, smoothing processing, differential processing, and integral processing in the contour map processing section 20 and the judgment method in the judgment section 30.

C: Second Embodiment FIG. 12 shows a functional block diagram of a non-destructive testing apparatus Z (including a non-destructive testing method) according to a second embodiment of the present invention. This non-destructive inspection device Z is for inspecting the existence and position of damaged parts of reinforcing bars 2 (inspection target steel materials 2) buried in a concrete body 1 from the outside without destroying the concrete body 1. More specifically, the reinforcing bars 2 are magnetized, the residual magnetic flux is measured from outside the concrete body 1 by a magnetic sensor to obtain a magnetic flux density waveform, and then a contour map is obtained based on this magnetic flux density waveform. The existence and position of damaged parts in the reinforcing bars 2 is then inspected from the linear characteristics of this contour map. Hereinafter, the contents of the non-destructive inspection apparatus Z will be specifically explained, although there are some parts that overlap with those already described.

"Non-destructive inspection device Z"
As shown in FIG. 12, the non-destructive testing device Z is configured to include a device main body Za and a magnetized section 41, which will be described below. Further, the apparatus main body Za includes a magnetic flux density measurement section 10, a contour map processing section 20, a determination section 30, and a display section 40. Note that these devices do not necessarily need to be housed in one housing, but may be independent devices and connected by wired or wireless communication lines.

The magnetized section 41 includes a magnet 8 . By placing this magnet 8 close to the surface 1a side of the concrete body 1 in which the reinforcing bars 2 as prestressing reinforcing bars and the cross reinforcing bars 3 substantially orthogonal to the reinforcing bars 2 are buried, or by moving the magnet 8 as appropriate. The reinforcing bars 2 are magnetized along the longitudinal direction without being After magnetization, the magnet 8 is removed from the concrete body surface 1a. Note that the function of the magnetizing section 41 corresponds to the "magnetizing step 48" in the non-destructive testing method.

"Magnetic flux density measurement section 10"
As shown in FIGS. 12 and 13, the magnetic flux density measurement unit 10 is a two-piece system that integrally incorporates a plurality of (seven in this embodiment) magnetic sensors 4 and distance sensors 7 arranged in a row at predetermined intervals. It is composed of two magnetic sensor units 5 and 6. Of these two magnetic sensor units 5 and 6, one magnetic sensor unit 5 is arranged close to the surface 1a of the concrete body 1 in a state substantially perpendicular to the longitudinal direction of the steel material to be inspected. In addition, the other magnetic sensor unit 6, like the magnetic sensor unit 5, is located approximately perpendicular to the longitudinal direction of the steel material to be inspected, and is spaced apart from the magnetic sensor unit 5 by a distance S upward (in the Z direction). It is placed in the same position. Each magnetic sensor 4 of these two magnetic sensor units 5 and 6 measures the residual magnetic flux of the reinforcing bar 2 to generate a magnetic flux density waveform.

The magnetism leaking to the outside from the reinforcing bar 2 is acquired by each magnetic sensor 4 of each of the magnetic sensor units 5 and 6 as an electric signal according to its magnitude. The measured value of the magnetic flux density measured by the magnetic sensor 4 is subjected to contour plotting processing in a contour plot processing unit 20, which will be described later, and is made into a contour plot (Figs. 14, 15, 17, 18, 20). , see FIGS. 21, 23, and 24).

Here, the reason why the magnetic sensor units 5 and 6 are configured to include a plurality of magnetic sensors 4 is to scan a wide range including the surrounding area of the reinforcing bar 2 at one time, thereby increasing work efficiency. However, instead of this configuration, for example, it is also possible to use a single magnetic sensor 4 and repeat scanning in the longitudinal direction while moving it by a predetermined width in a direction (Y direction) perpendicular to the longitudinal direction of the reinforcing bars 2. can.

Furthermore, the reason why the two magnetic sensor units 5 and 6 are arranged apart in the Z direction is that the detected values of the respective magnetic sensors 4 of the two magnetic sensor units 5 and 6 having different heights can be adjusted as described below. The contour map based on the reinforcing bars 2 is emphasized by combining the two contour maps obtained based on the above-mentioned bases by calculation and eliminating the diagram based on the intersecting reinforcing bars 3 located near the reinforcing bars 2 as noise. This is to display the Note that the function of the magnetic flux density measuring section 10 corresponds to the "magnetic flux density measuring step 45" in the non-destructive testing method.

“Contour map processing unit 20”
The contour map processing section 20 includes a raw line diagram generation section 21 , a flattening processing section 22 , a smoothing processing section 23 , a differential processing section 24 , and an integral processing section 25 . Further, the smoothing processing section 23 is connected to the calculation processing section 13, the differentiation processing section 24 is connected to the calculation processing section 14, and the integration processing section 25 is connected to the calculation processing section 15 in a control manner. There is.

The raw line diagram generating unit 21 converts the Z-axis direction component of the magnetic flux density measurement value obtained by each magnetic sensor 4 of each magnetic sensor unit 5, 6 of the magnetic flux density measuring unit 10 into a longitudinal direction of the reinforcing bar 2. They are contour plotted in relation to the measurement position in the direction and shown as one raw contour map and another raw contour map (not shown). This first raw contour map and the other raw contour maps are used as contour maps that form the basis of each process in the flattening processing section 22 to the integration processing section 25 described below. Note that this processing step in the raw line diagram generation unit 21 corresponds to the "first processing step 51" in the nondestructive testing method.

“Flattening processing unit 22”
The flattening processing unit 22 performs a flattening process to subtract a longitudinal linear change in magnetic flux density from each of the first raw contour map and the other raw contour map obtained by the raw line diagram generation unit 21. and obtain one flattened contour map and another flattened contour map (not shown).

“Smoothing processing unit 23”
The smoothing processing unit 23 performs a smoothing process in the longitudinal direction on each of the one flattened contour map and the other flattened contour map acquired by the flattening processing unit 22, and generates one smoothed contour map. and other smoothed contour maps, respectively.

The first smoothed contour diagram shown in FIG. 14 corresponds to the Z-axis direction component of the bipolar magnetic flux density waveform, and when the direction of magnetic flux due to magnetization is the longitudinal direction of the reinforcing steel (X-axis direction). , the maximum part and the minimum part appear in the order of "maximum part → minimum part", the maximum part and the minimum part are antisymmetric with respect to the Y direction axis n, and the maximum part appears with respect to the X direction axis m. Both the part and the minimum part are symmetrical.

The other smoothed contour diagram shown in FIG. 15 corresponds to the Z-axis direction component of the bipolar magnetic flux density waveform, and when the direction of magnetic flux due to magnetization is the longitudinal direction of the reinforcing steel (X-axis direction). , the maximum part and the minimum part appear in the order of "maximum part → minimum part", the maximum part and the minimum part are antisymmetric with respect to the Y direction axis n, and the maximum part appears with respect to the X direction axis m. The part and the minimum part are each symmetrical.

“Arithmetic processing unit 13”
The arithmetic processing unit 13 combines the first smoothed contour map and the other smoothed contour map by calculation, assuming that the buried depth of the reinforcing bars 2 read from the buried depth data 43 is known, and performs composite smoothing. A contour map is obtained, and this composite flattened contour map is handled as a determination target in a determination unit 30, which will be described later.

Here, the calculation method in the calculation processing section 13 will be explained.
The distance between the first magnetic sensor unit 5 placed near the surface 1a of the concrete body 1 and the reinforcing bar 2 buried in the concrete body 1 is defined as "ZN _0" , If the distance between the other magnetic sensor unit 6 and the reinforcing bar 2, which are arranged apart from each other, is "ZF _0" , then "ZF ₀ =ZN ₀ +ΔZ".
However, "ΔZ" is the distance in the Z direction between one magnetic sensor unit 5 and another magnetic sensor unit 5 (indicated as "S" in FIG. 13).
Here, it is assumed that the buried depth of the reinforcing bar 2 from the surface of the concrete body in the Z direction is known (read from the "buried depth data 43" in FIG. 12).
Then, the ratio "ZN ₀ /ZF ₀ " of the distances between the magnetic sensor unit 5 of the concrete body 1, other magnetic sensor units 6, and the reinforcing bars 2 is also known, and its δ power (power) is "α ₀ ". If so, it is also known.
If the ratio "α=SF/SN" at the same point in the contour map of one magnetic sensor unit 5 and the other magnetic sensor unit 6 matches the above "α _0" , "F(α)=1", and they match. If not, define a function ``F(α)'' such that ``F(α) = approximately O'' and multiply the first contour map by ``F(α)'' to create a composite contour map. A composite contour map is obtained that emphasizes the contribution of reinforcing bar 2.
For example, if "F(α)=EXP(-|LN(α/α ₀ ) | × γ))", if "α=α _0" , "F(α)=1", α>α ₀ In the case of , "F(α) = (α ₀ / α) to the γ power", and in the case of α < α ₀ , "F(α) = (α / α ₀ ) to the γ power", and as γ increases, "F(α)" approaches O.

The composite smoothed contour diagram shown in FIG. 16 corresponds to the Z-axis direction component of the bipolar magnetic flux density waveform, and when the direction of magnetic flux due to magnetization is the longitudinal direction (X-axis direction) of the reinforcing steel, In this case, the maximum part and the minimum part appear in the order of "maximum part → minimum part", the maximum part and the minimum part are antisymmetric with respect to the Y direction axis n, and the maximum part appears with respect to the X direction axis m. and the minimum part are symmetrical (see Table 2). It is estimated that the intersection of the X-direction axis m and the Y-direction axis n is the damaged part of the reinforcing bar 2. Therefore, this flattened contour map can be used in the determining section 30, which will be described later, to determine the presence or absence and position of a damaged portion of the reinforcing bar 2.

“Differential processing unit 24”
The differential processing unit 24 performs first-order and multiple-order differential processing on each of the first smoothed contour map and the other smoothed contour map in the longitudinal direction, and calculates the first-order differential contour map and the multiple-order differentials. This is to obtain a contour map (for example, a second-order differential contour map, a third-order differential contour map, a fourth-order differential contour map, etc.), and in this embodiment, one first-order differential contour map based on one magnetic sensor unit 5 is obtained. is shown in FIG. 17, and another first-order differential contour map based on another magnetic sensor unit 6 is shown in FIG. 18, respectively. Further, one second-order differential contour map based on one magnetic sensor unit 5 is shown in FIG. 20, and another second-order differential contour map based on another magnetic sensor unit 6 is shown in FIG. 21, respectively.

The first-order differential contour diagram shown in FIG. 17 corresponds to the Z-axis direction component of the unimodal magnetic flux density waveform, and when the direction of magnetic flux due to magnetization is in the longitudinal direction of the reinforcing steel, , has a minimum part, and this minimum part is symmetrical in each of the X-direction axis m and the Y-direction axis n (see Table 2).

The other first-order differential contour diagram shown in FIG. 18 corresponds to the Z-axis direction component of the unimodal magnetic flux density waveform, and when the direction of magnetic flux due to magnetization is in the longitudinal direction of the reinforcing steel, , has a minimum part, and this minimum part is symmetrical about the X-direction axis m and the Y-direction axis n (see Table 2).

The first second-order differential contour diagram shown in FIG. 20 corresponds to the Z-axis direction component of the bipolar magnetic flux density waveform, and when the direction of the magnetic flux due to magnetization is the longitudinal direction of the reinforcing steel, The maximum part and the minimum part appear in the order of "minimum part → maximum part", and the minimum part and maximum part are antisymmetrical with respect to the Y direction axis n and symmetrical with respect to the X direction axis m. (See Table 2).

The other second-order differential contour diagram shown in FIG. 21 corresponds to the Z-axis direction component of the bipolar magnetic flux density waveform, and when the direction of the magnetic flux due to magnetization is the longitudinal direction of the reinforcing steel, The maximum part and the minimum part appear in the order of "minimum part → maximum part", and the minimum part and maximum part are antisymmetrical with respect to the Y direction axis n and symmetrical with respect to the X direction axis m. (See Table 2).

Although not shown, the third-order differential contour map corresponds to the Z-axis direction component of the unimodal magnetic flux density waveform, and when the direction of the magnetic flux due to magnetization is the longitudinal direction of the reinforcing steel, It is a single-modal contour map with a maximum part, and this maximum part is symmetrical in both the X-direction axis m and the Y-direction axis n (see Table 2).

Although not shown, the fourth-order differential contour map corresponds to the Z-axis direction component of the bipolar magnetic flux density waveform, and when the direction of the magnetic flux due to magnetization is in the longitudinal direction of the reinforcing steel, the maximum The maximum part and the minimum part appear in the order of "maximum part → minimum part", and the maximum part and the minimum part are antisymmetric with respect to the Y-direction axis n, and the maximum part and the minimum part with respect to the X-direction axis m. It is symmetrical (see Table 2).

In this way, the differential contour maps of odd-numbered orders are both unimodal, but as the rank changes, they change from unimodal (first-order differential contour) with a minimum to a maximum. The minimum and maximum parts alternately change to a single peak shape (third-order differential contour map) with (see Table 2).

On the other hand, even-numbered differential contour maps are bipolar differential contour maps, but as the rank changes, the order in which the maximum and minimum parts appear changes from "minimum part to maximum part" (second-order differential contour map). (Differential contour map) changes from "maximum part to minimum part" (4th order differential contour map) (see Table 2).

“Arithmetic processing unit 14”
The arithmetic processing unit 14 calculates the first-order differential contour map (FIG. 17) and the other differential contour map (FIG. 18) by assuming that the buried depth of the reinforcing bars 2 read from the buried depth data 43 is known. 19 to obtain the composite first-order differential contour map shown in FIG. Assuming that the burial depth is known, the composite second-order differential contour map shown in FIG. It can be used to determine the presence or absence and position of a damaged part in the section 30.

The composite first-order differential contour diagram shown in FIG. 19 corresponds to the Z-axis direction component of the unimodal magnetic flux density waveform, and when the direction of magnetic flux due to magnetization is the longitudinal direction of the reinforcing steel, This minimum portion is symmetrical with respect to the X-direction axis m and the Y-direction axis n (see Table 2). It is estimated that the intersection of the X-direction axis m and the Y-direction axis n is the damaged part of the reinforcing bar 2. Therefore, this composite first-order differential contour map can be used in the determining section 30, which will be described later, to determine the presence or absence and position of a damaged portion of the reinforcing bar 2.

The composite second-order differential contour diagram shown in FIG. 22 corresponds to the Z-axis direction component of the bipolar magnetic flux density waveform, and when the direction of magnetic flux due to magnetization is in the longitudinal direction of the reinforcing steel, The maximum part and minimum part appear in the order of "minimum part → maximum part", and the maximum part and minimum part are antisymmetrical with respect to the Y direction axis n, and the maximum part and minimum part are with respect to the X direction axis m. It is symmetrical (see Table 2). It is estimated that the intersection of the X-direction axis m and the Y-direction axis n is the damaged part of the reinforcing bar 2. Therefore, this composite second-order differential contour map can be used in the determining section 30, which will be described later, to determine the presence or absence and position of a damaged portion of the reinforcing bar 2.

“Integral processing unit 25”
The integral processing unit 25 performs first-order integration in the longitudinal direction on the one smoothed contour map and the other smoothed contour map, respectively, to obtain one first-order integral contour map and another first-order integral contour map. This first-order integral contour map is shown in FIG. 23, and the other first-order integral contour map is shown in FIG.

If the direction of the magnetic flux due to magnetization is in the longitudinal direction of the reinforcing steel, the first-order integral contour diagram shown in FIG. It is symmetrical in both the m and Y direction axes n (see Table 2). In addition, the other first-order integral contour map shown in FIG. 24 shows a single peak shape when the scanning direction of each of the magnetic sensor units 5 and 6 is the longitudinal direction (X-axis direction) of the reinforcing bar 2. The maximum part is symmetrical in both the X-direction axis m and the Y-direction axis n (see Table 2).

“Arithmetic processing unit 15”
The arithmetic processing unit 15 calculates the buried depth of the reinforcing bars 2 read from the buried depth data 43 by using the one first-floor integral contour map shown in FIG. 23 and the other first-floor integral contour map shown in FIG. As is known, the composite first-order integral contour map shown in FIG. 25 is obtained by combining by calculation, and this composite first-order integral contour map can be used in the determination section 30 described later to determine the presence or absence of a damaged part and its position. .

This composite first-order integral contour map corresponds to the Z-axis direction component of the unimodal magnetic flux density waveform, and if the direction of magnetic flux due to magnetization is in the longitudinal direction of the reinforcing steel, it has a maximum part. Moreover, this maximum portion is symmetrical about the X-direction axis m and the Y-direction axis n (see Table 2). It is estimated that the intersection of the X-direction axis m and the Y-direction axis n is the damaged part of the reinforcing bar 2. Therefore, this composite first-order integral contour map can be used in the determining section 30, which will be described later, to determine the presence or absence and position of a damaged portion of the reinforcing bar 2. Note that the function of the contour map processing section 20 corresponds to the "contour map processing step 46" in the non-destructive testing method.

“Judgment unit 30”
The determination unit 30 determines the presence or absence and position of the damaged portion of the reinforcing bars 2 based on the composite contour map acquired by the contour map processing unit 20, and includes a determination target selection unit 31 and a first determination processing unit. 32, a determination accuracy determining section 33, and a second determination processing section 34.

The determination target selection unit 31 selects the external visibility of the concrete body 1 and the reinforcing bars 2 from among the composite smoothed contour map, composite differential contour map, and composite integral contour map acquired in the contour map processing unit 20. Select a composite contour map that is considered to be appropriate based on the buried state etc.

The first determination processing unit 32 compares the composite contour map selected by the determination target selection unit 31 with a preset determination reference value 42, and determines whether or not there is a damaged part of the reinforcing bar 2 according to the selected contour map. and determine the position detection accuracy. If it is determined that the accuracy is at a predetermined level or higher, the selected contour map and the determination results of the existence and position of damaged parts of the reinforcing bars 2 are displayed on the display unit 40.

On the other hand, if the determination accuracy determination unit 33 determines that the accuracy level has not been reached to a sufficient level, the second determination processing unit 34 selects another contour map different from the previously selected contour map. , re-select this contour map and compare it with the above-mentioned judgment reference value 42 to re-judge the determination accuracy of the contour map, and display the contour map and the determination results of the presence/absence and position of damaged parts of reinforcing bars 2 on the display section. 40. Note that it is optional whether the determination accuracy in this contour map is re-determined only once or multiple times.

In addition, the above-mentioned judgment standard value 42 is a standard when inspecting the presence or absence of damaged parts of reinforcing bars 2 and the damaged position using each of the above-mentioned contour maps, for example, as a mock-up for each smoothed contour map, differential contour map, and integral contour map. These settings are confirmed and set in advance through close-up measurements and the like.

Here, "Table 2" is shown which summarizes the processing methods of flattening processing, smoothing processing, differential processing, and integral processing in the contour map processing section 20 and the judgment method in the judgment section 30.

D: Third Embodiment FIG. 26 shows a functional block diagram of a non-destructive testing apparatus Z (including a non-destructive testing method) according to a third embodiment of the present invention. This non-destructive testing device Z detects the presence or absence of damage to the reinforcing bars 2 (inspected steel material 2) buried in the concrete body 1 and the burial depth of the reinforcing bars 2 from the surface 1a of the concrete body 1. 1 from the outside without destroying the concrete body 1. More specifically, the reinforcing steel 2 is magnetized, and its residual magnetic flux is measured from the outside of the concrete body 1 with a magnetic sensor to obtain a magnetic flux density waveform. Thereafter, a contour map is obtained based on this magnetic flux density waveform, and the buried depth of the reinforcing bars 2 is determined from the linear characteristics of this contour map. Hereinafter, the contents of the non-destructive inspection apparatus Z will be specifically explained, although there are some parts that overlap with those already described. Regarding the drawings, some drawings of the second embodiment will be referred to.

"Non-destructive inspection device Z"
As shown in FIG. 26, the non-destructive testing device Z is configured to include a device main body Za and a magnetized section 41, which will be described below. Furthermore, the apparatus main body Za is configured to include a magnetic flux density measurement section 10, a contour map processing section 20, a determination section 30, an output section 38, and a display section 40.

The magnetized section 41 includes a magnet 8 . By placing this magnet 8 close to the surface 1a side of the concrete body 1 in which the reinforcing bars 2 as prestressing reinforcing bars and the cross reinforcing bars 3 substantially orthogonal to the reinforcing bars 2 are buried, or by moving the magnet 8 as appropriate. The reinforcing bars 2 are magnetized along the longitudinal direction without being After magnetization, the magnet 8 is removed from the concrete body surface 1a. Note that the function of the magnetizing section 41 corresponds to the "magnetizing step 48" in the non-destructive testing method.

"Magnetic flux density measurement section 10"
As shown in FIG. 26 (and FIG. 13), the magnetic flux density measurement unit 10 integrates a plurality of (seven in this embodiment) magnetic sensors 4 and distance sensors 7 arranged in a line at predetermined intervals. It is composed of two built-in magnetic sensor units 5 and 6. Of these two magnetic sensor units 5 and 6, one magnetic sensor unit 5 is arranged close to the surface 1a of the concrete body 1 in a state substantially perpendicular to the longitudinal direction of the steel material to be inspected. In addition, the other magnetic sensor unit 6, like the magnetic sensor unit 5, is located approximately perpendicular to the longitudinal direction of the steel material to be inspected, and is spaced apart from the magnetic sensor unit 5 by a distance S upward (in the Z direction). It will be placed in the same position. Each magnetic sensor 4 of these two magnetic sensor units 5 and 6 measures the residual magnetic flux of the reinforcing bar 2 to generate a magnetic flux density waveform.

The magnetism leaking to the outside from the reinforcing bar 2 is acquired by each magnetic sensor 4 of each of the magnetic sensor units 5 and 6 as an electric signal according to its magnitude. The measured value of the magnetic flux density measured by the magnetic sensor 4 is subjected to contour plotting processing in a contour plot processing unit 20, which will be described later, and is made into a contour plot (Figs. 14, 15, 17, 18, 20). , see FIGS. 21, 23, and 24).

Here, the reason why each of the magnetic sensor units 5 and 6 is provided with a plurality of magnetic sensors 4 is to scan a wide range including the surrounding area of the reinforcing bar 2 at one time to increase work efficiency. Instead of such a configuration, for example, a single magnetic sensor 4 may be used and scanning in the longitudinal direction may be repeated while moving it by a predetermined width in a direction perpendicular to the longitudinal direction of the reinforcing bar 2 (Y direction).

Moreover, the reason why the two magnetic sensor units 5 and 6 are arranged apart in the Z direction is that the concrete body of the reinforcing bar 2 is detected based on the detected values of the two magnetic sensors 4 having different heights, as described below. This is to find the burial depth from the surface. Note that the function of the magnetic flux density measuring section 10 corresponds to the "magnetic flux density measuring step 45" in the non-inspection method.

“Contour map processing unit 20”
The contour map processing section 20 includes a raw line diagram generation section 21 , a flattening processing section 22 , a smoothing processing section 23 , a differential processing section 24 , and an integral processing section 25 .

“Raw diagram generation unit 21”
The raw line diagram generating unit 21 converts the Z-axis direction component of the magnetic flux density measurement value obtained by each magnetic sensor 4 of each magnetic sensor unit 5, 6 of the magnetic flux density measuring unit 10 into a longitudinal direction of the reinforcing bar 2. A contour map is created in relation to the measurement position in the direction and obtained as one raw contour map and another raw contour map (not shown). This first raw contour map and other raw contour maps are used as contour diagrams that serve as the basis for each process in the flattening processing section 22, smoothing processing section 23, differential processing section 24, and integral processing section 25 described below. used as.

“Flattening processing unit 22”
The flattening processing unit 22 performs a flattening process to subtract a longitudinal linear change in magnetic flux density from each of the first raw contour map and the other raw contour map obtained by the raw line diagram generation unit 21. Then, one flattened contour map and another flattened contour map are obtained, respectively (not shown).

“Smoothing processing unit 23”
The smoothing processing section 23 smoothes each of the one flattened contour map and the other flattened contour map acquired by the flattening processing section 22 in the longitudinal direction of the magnetic flux density, and generates one smoothed contour map. (see FIG. 14) and another smoothed contour map (see FIG. 15), respectively.

The first smoothed contour diagram (see Figure 14) above corresponds to the Z-axis direction component of the bipolar magnetic flux density waveform, and the direction of magnetic flux due to magnetization is in the longitudinal direction (X-axis direction) of the reinforcing steel. In some cases, the maximum part and the minimum part appear in the order of "maximum part → minimum part", and the maximum part and the minimum part are antisymmetric with respect to the Y-direction axis n, and with respect to the X-direction axis m. Both the maximum and minimum parts are symmetrical (see Table 3). It is estimated that the intersection of the X-direction axis m and the Y-direction axis n is the damaged part of the reinforcing bar 2. Therefore, this smoothed contour map can be used by the determining section 30, which will be described later, to determine whether there is a damaged portion of the reinforcing bar 2 and the depth of its burial.

The other smoothed contour diagrams mentioned above (see Figure 15) correspond to the Z-axis direction component of the bipolar magnetic flux density waveform, and the direction of the magnetic flux due to magnetization is the longitudinal direction of the reinforcing steel (X-axis direction). In some cases, the maximum part and the minimum part appear in the order of "maximum part → minimum part", and the maximum part and the minimum part are antisymmetric with respect to the Y-direction axis n, and with respect to the X-direction axis m. Both the maximum and minimum parts are symmetrical (see Table 3). It is estimated that the intersection of the X-direction axis m and the Y-direction axis n is the damaged part of the reinforcing bar 2. Therefore, this smoothed contour map can be used by the determining section 30, which will be described later, to determine whether there is a damaged portion of the reinforcing bar 2 and the depth of its burial.

“Differential processing unit 24”
The differential processing unit 24 performs first-order and multiple-order differential processing on each of the first smoothed contour map and the other smoothed contour map in the longitudinal direction, and calculates the first-order differential contour map and the multiple-order differentials. A contour map (for example, a second-order differential contour map, a third-order differential contour map, a fourth-order differential contour map, etc.) is obtained, and in this embodiment, one first-order differential contour map based on the measurement of one magnetic sensor unit 5 is obtained. A contour map (see FIG. 17) and another first-order differential contour map (see FIG. 18) based on measurements of other magnetic sensor units 6 are obtained.

The above-mentioned first-order differential contour diagram (see Figure 17) corresponds to the Z-axis direction component of the unimodal magnetic flux density waveform, and the direction of the magnetic flux due to magnetization is in the longitudinal direction of the reinforcing steel (X-axis direction). ), it has a minimum part, and this minimum part is symmetrical in both the X-direction axis m and the Y-direction axis n (see Table 3). It is estimated that the intersection of the X-direction axis m and the Y-direction axis n is the damaged part of the reinforcing bar 2. Therefore, this first-order differential contour map can be used by the determining section 30, which will be described later, to determine the presence or absence of a damaged portion of the reinforcing bar 2 and its burial depth.

The other first-order differential contour map (see FIG. 18) above corresponds to the Z-axis direction component of the unimodal magnetic flux density waveform, and the direction of the magnetic flux due to magnetization is in the longitudinal direction of the reinforcing steel (X-axis direction). ), it has a minimum part, and this minimum part is symmetrical in both the X direction axis m and the Y direction axis n (see Table 3). It is estimated that the intersection of the X-direction axis m and the Y-direction axis n is the damaged part of the reinforcing bar 2. Therefore, this other first-order differential contour map can be used by the determination unit 30, which will be described later, to determine the presence or absence of a damaged portion of the reinforcing bar 2 and its burial depth.

The first second-order differential contour diagram (see Figure 20) above corresponds to the Z-axis direction component of the bipolar magnetic flux density waveform, and the direction of the magnetic flux due to magnetization is the longitudinal direction of the reinforcing steel (X-axis direction). In this case, the maximum part and the minimum part appear in the order of "minimum part → maximum part", and the minimum part and the maximum part are antisymmetric with respect to the Y-direction axis n, and the It is symmetrical for (see Table 3). It is estimated that the intersection of the X-direction axis m and the Y-direction axis n is the damaged part of the reinforcing bar 2. Therefore, this other second-order differential contour map can be used by the determination unit 30, which will be described later, to determine the presence or absence of a damaged portion of the reinforcing bar 2 and its burial depth.

The other second-order differential contour map (see Figure 21) corresponds to the Z-axis direction component of the bipolar magnetic flux density waveform, and the direction of the magnetic flux due to magnetization is the longitudinal direction of the reinforcing steel (X-axis direction). In the case where It is antisymmetric (see Table 3). It is estimated that the intersection of the X-direction axis m and the Y-direction axis n is the damaged part of the reinforcing bar 2. Therefore, this other second-order differential contour map can be used by the determination unit 30, which will be described later, to determine the presence or absence of a damaged portion of the reinforcing bar 2 and its burial depth. It should be noted that the explanation of the contour diagrams higher than the third-order differential contour diagram will be omitted.

In this way, the differential contour maps of odd-numbered orders are both unimodal, but as the rank changes, they change from unimodal (first-order differential contour) with a minimum to a maximum. The minimum and maximum parts alternately change to a single peak shape (third-order differential contour map) with (see Table 3).

On the other hand, even-numbered differential contour maps are bipolar differential contour maps, but as the rank changes, the order in which the maximum and minimum parts appear changes from "minimum part to maximum part" (second-order differential contour map). (Differential contour map) changes from "maximum part to minimum part" (4th order differential contour map) (see Table 3).

“Integral processing unit 25”
The integral processing unit 25 performs first-order integration in the longitudinal direction on the first smoothed contour map (see FIG. 14) and the other smoothed contour map (see FIG. 15), and calculates one first-order integral contour. (see FIG. 23) and another first-order integral contour map (see FIG. 24).

If the direction of the magnetic flux due to magnetization is in the longitudinal direction of the reinforcing steel (X-axis direction), the above-mentioned first-order integral contour diagram (see Fig. 23) becomes a contour diagram with a single-peak maximum part, and This maximum portion is symmetrical in both the X direction axis m and the Y direction axis n (see Table 3). It is estimated that the intersection of the X-direction axis m and the Y-direction axis n is the damaged part of the reinforcing bar 2. Therefore, this first-order integral contour map can be used by the determining section 30, which will be described later, to determine the presence or absence of a damaged portion of the reinforcing bar 2 and the burial depth.

If the direction of magnetic flux due to magnetization is in the longitudinal direction of the reinforcing steel (X-axis direction), the other first-order integral contour map (see FIG. 24) will be a contour map with a unimodal maximum part, and This maximum portion is symmetrical in both the X-direction axis m and the Y-direction axis n. It is estimated that the intersection of the X-direction axis m and the Y-direction axis n is the damaged part of the reinforcing bar 2. Therefore, this first-order integral contour map can be used by the determination unit 30, which will be described later, to determine the presence or absence of a damaged portion of the reinforcing bar 2 and the burial depth.

Here, "Table 3" is shown which summarizes the processing methods of smoothing processing, differential processing, and integral processing in the contour map processing section 20 and the judgment method in the judgment processing section 38.

“Judgment unit 30”
The determination section 30 includes a determination processing section 36 and a buried depth calculation section 37. The determination processing section 36 selects one of the smoothed contour map, differential contour map, and integral contour map acquired in the contour map processing section 20, and uses the selected contour map and the preset judgment criteria. By comparing the value 42, it is determined whether the reinforcing bar 2 is damaged or not. If it is determined that there is damage, the signal is output to the burial depth calculation section 37. That is, the determination that there is a damaged portion is a condition for calculating the burial depth of the reinforcing bars 2.

Then, the buried depth calculation section 37 receives the signal from the determination processing section 36 and calculates the buried depth of the reinforcing bar 2 from the surface of the concrete body 1.

Here, the calculation formula for estimating the burial depth of the reinforcing bars 2 is as follows.
・The distance between the magnetic sensor unit 5 and the reinforcing bar 2 (steel material to be inspected) is "ZN ₀ "
- The distance “ZF ₀ ” between the magnetic sensor unit 6 and the reinforcing bar 2 is set as “ZF ₀ =ZN ₀ +△Z”.
However, ΔZ is the distance between the sensor units 5 and 6 in the Z direction.
- The height of the maximum part (or minimum part) of the magnetic sensor unit 5 when it is determined that the reinforcing bar 2 is "damaged" is "SN ₀ ", and the height of the maximum part (or minimum part) of the magnetic sensor unit 6 is Let the height be “SF ₀ ”,
-Approximate "ZN ₀ /ZF ₀ =ZN ₀ /(ZN ₀ +△Z)" by the δth root (power root) β ₀ of (SF ₀ /SN ₀ ).
_- Therefore, _" ZN ₀ = △ _Z The position (buried depth = “ZN ₀ -z)” is determined.

The "embedding depth" of the reinforcing bars 2 calculated in the embedding depth calculating section 37 can be displayed on the display section 40, so that, for example, in repair work of a structure related to the concrete body 1, the reinforcing bars 2 can be It can contribute to the efficient implementation of various construction and inspection tasks, such as determining the "embedding depth" of concrete and accurately setting concrete.

Further, the "burying depth" is outputted from the output section 38 as necessary. For example, in the non-destructive testing apparatus Z of the second embodiment, in a case where the "embedding depth" of the reinforcing bars 2 is not known (for example, the burying depth of the reinforcing bars 2 cannot be known from a design drawing, etc.). In such a case, the above-mentioned "embedding depth" determined here can be used instead of this known "embedding depth."

The non-destructive testing method and testing device according to the present invention can be used for non-destructive testing to detect the presence and/or location of damaged parts of steel materials buried in concrete bodies, such as bridges, buildings, or concrete poles. be.

1...Concrete body 2...Reinforcing bars (steel material to be inspected)
3... Magnet 4... Magnetic sensor 5, 6... Magnetic sensor unit 7... Distance sensor 8... Magnet 10... Magnetic flux density measuring unit 20... Contour map processing unit 21... Raw line diagram generating unit 22 - Flattening processing section 23 ... Smoothing processing section 24 ... Differential processing section 25 ... Integral processing section 30 ... Judgment section 31 ... Judgment target selection section 32 ... First judgment processing section 33 ... Judgment accuracy judgment Section 34...Second judgment processing section 36...Judgment processing section 37...Burial depth calculation section 38...Output section 40...Display section 42...Judgment reference value 43...Burial depth data 45...Magnetic flux Density measurement process 46...Contour map processing process 47...Judgment process 48...Magnetization process Za...Device body Z...Non-destructive testing device

Claims (12)

By magnetizing the steel material to be inspected from the outside of the concrete body in which the steel material to be inspected is buried with a magnet, and then measuring the magnetic flux density of the concrete body with a magnetic sensor, it is possible to determine whether or not there is a damaged part of the steel material to be inspected. / and a non-destructive testing method for detecting the position,
a magnetization step of arranging the magnetized surface of the magnet close to the surface of the concrete body and then magnetizing the steel material to be inspected along its longitudinal direction by moving it appropriately or without moving it;
After arranging a magnetic sensor unit having a plurality of magnetic sensors arranged in a row close to the surface of the concrete body with the direction in which the magnetic sensors are arranged substantially perpendicular to the longitudinal direction of the steel material to be inspected, A magnetic flux density measuring step of measuring the magnetic flux density of the steel material to be inspected by or without moving the steel material in the longitudinal direction;
A raw contour map generation process that generates a magnetic flux density contour map based on the magnetic flux density measured in the magnetic flux density measurement step, and a flattened contour map by subtracting a linear change in the longitudinal direction of the magnetic flux density from the raw contour map. a smoothing process to obtain a smoothed contour map, a smoothing process to obtain a smoothed contour map by smoothing the flattened contour map in the longitudinal direction, and a first-order or multiple-order differential in the longitudinal direction for the smoothed contour map. At least the above-mentioned raw contour map generation process and the above-mentioned flattening process. or at least the above raw contour map generation process, the flattening process and the smoothing process, or at least the above raw contour map generation process and the differentiation process, or at least the above raw contour map generation process and a contour map processing step of performing the flattening processing and integration processing;
Compare any one of the flattened contour map, smoothed contour map, differential contour map, and integral contour map with a predetermined criterion value to determine the presence and/or location of damaged parts in the steel material to be inspected. and a determination step of
The above judgment standard value is
The direction of the magnetic flux within the steel material to be inspected is the longitudinal direction of the steel material to be inspected, and the magnetic flux density component in a direction substantially orthogonal to the surface of the concrete body, or its differential or integral in the longitudinal direction, is substantially orthogonal to the surface of the concrete body. When drawing a contour map with the direction away from the steel material being inspected as positive and the opposite direction as negative,
In the judgment using the flattened contour map or the smoothed contour map, the maximum and minimum parts of the contour line appear sequentially in the longitudinal direction of the steel to be inspected, and the maximum and minimum parts are located in the longitudinal direction of the steel to be inspected. When in the direction it is bipolar, antisymmetrical about the orthogonal axis, and in the orthogonal direction, it is unimodal, symmetrical about the longitudinal axis,
In the judgment using the above differential contour map, in the second order or (2+4n) order differential among the even number of differentiations, the minimum and maximum parts of the contour line appear sequentially in the longitudinal direction of the steel material to be inspected, and the minimum and maximum parts appear sequentially in the longitudinal direction of the steel material to be inspected. When the part is bipolar in the longitudinal direction of the steel to be inspected, which is antisymmetrical to the orthogonal direction axis, and in the orthogonal direction, it is a monomodal shape that is symmetrical to the longitudinal direction (n is a natural number),
Furthermore, in the 4th or (4+4n) order differential among the even-numbered differentiations, the maximum and minimum parts of the contour line appear sequentially in the longitudinal direction of the steel material to be inspected, and the maximum and minimum parts of the contour line appear in the longitudinal direction of the steel material to be inspected. When it becomes a bipolar shape that is antisymmetric about the orthogonal direction axis, and a unimodal shape that is symmetric about the longitudinal axis in the orthogonal direction (n is a natural number),
Each of these values is preset to indicate that the intersection of the longitudinal axis and the orthogonal axis of the steel material to be inspected is a damaged portion of the steel material to be inspected,
Or, the above judgment standard value is
The direction of the magnetic flux within the steel material to be inspected is a direction opposite to the longitudinal direction of the steel material to be inspected, and the magnetic flux density component in a direction approximately perpendicular to the surface of the concrete body, or its differential or integral in the longitudinal direction is the surface of the concrete body. When drawing a contour map with the direction substantially perpendicular to the steel material and moving away from the steel material to be inspected as positive and the opposite direction as negative,
In the judgment using the flattened contour map or the smoothed contour map, the minimum and maximum parts of the contour line appear sequentially in the longitudinal direction of the steel to be inspected, and the minimum and maximum parts are located in the longitudinal direction of the steel to be inspected. When in the direction it is bipolar, antisymmetrical about the orthogonal axis, and in the orthogonal direction, it is unimodal, symmetrical about the longitudinal axis,
In the judgment using the above differential contour map, in the second order or (2+4n) order differential among the even number of differentiations, the maximum and minimum parts of the contour line appear sequentially in the longitudinal direction of the steel material to be inspected, and the maximum and minimum parts appear sequentially in the longitudinal direction of the steel material to be inspected. When the part is bipolar in the longitudinal direction of the steel to be inspected, which is antisymmetrical to the orthogonal direction axis, and in the orthogonal direction, it is a monomodal shape that is symmetrical to the longitudinal direction (n is a natural number),
Furthermore, in the 4th or (4+4n) order differential among the even-numbered differentiations, the minimum and maximum parts of the contour lines appear sequentially in the longitudinal direction of the steel material to be inspected, and the minimum and maximum parts are in the longitudinal direction of the steel material to be inspected. When it becomes a bipolar shape that is antisymmetric about the orthogonal direction axis, and a unimodal shape that is symmetric about the longitudinal axis in the orthogonal direction (n is a natural number),
A non-destructive testing method characterized in that each of the values is preset to indicate that the intersection of the longitudinal axis and the orthogonal axis of the steel material to be inspected is a damaged portion of the steel material to be inspected. By magnetizing the steel material to be inspected from the outside of the concrete body in which the steel material to be inspected is buried with a magnet, and then measuring the magnetic flux density of the concrete body with a magnetic sensor, it is possible to determine whether or not there is a damaged part of the steel material to be inspected. / and a non-destructive testing method for detecting the position,
a magnetization step of arranging the magnetized surface of the magnet close to the surface of the concrete body and then magnetizing the steel material to be inspected along its longitudinal direction by moving it appropriately or without moving it;
After arranging a magnetic sensor unit having a plurality of magnetic sensors arranged in a row close to the surface of the concrete body with the direction in which the magnetic sensors are arranged substantially perpendicular to the longitudinal direction of the steel material to be inspected, A magnetic flux density measuring step of measuring the magnetic flux density of the steel material to be inspected by or without moving the steel material in the longitudinal direction;
A raw contour map generation process that generates a magnetic flux density contour map based on the magnetic flux density measured in the magnetic flux density measurement step, and a flattened contour map by subtracting a linear change in the longitudinal direction of the magnetic flux density from the raw contour map. a smoothing process to obtain a smoothed contour map, a smoothing process to obtain a smoothed contour map by smoothing the flattened contour map in the longitudinal direction, and a first-order or multiple-order differential in the longitudinal direction for the smoothed contour map. At least the above-mentioned raw contour map generation process and the above-mentioned flattening process. or at least the above raw contour map generation process, the flattening process and the smoothing process, or at least the above raw contour map generation process and the differentiation process, or at least the above raw contour map generation process and a contour map processing step of performing the flattening processing and integration processing;
Compare any one of the flattened contour map, smoothed contour map, differential contour map, and integral contour map with a predetermined criterion value to determine the presence and/or location of damaged parts in the steel material to be inspected. and a determination step of
The above judgment standard value is
The direction of the magnetic flux within the steel material to be inspected is the longitudinal direction of the steel material to be inspected, and the magnetic flux density component in a direction substantially orthogonal to the surface of the concrete body, or its differential or integral in the longitudinal direction, is substantially orthogonal to the surface of the concrete body. When drawing a contour map with the direction away from the steel material being inspected as positive and the opposite direction as negative,
In the determination using the above differential contour map, the minimum part of the contour line is the first or (1+4n) order of odd-order differentiation, and the maximum part of the contour line is the third-order or (3+4n) order of odd-order differentiation. When each of the above-mentioned steel materials to be inspected has a symmetrical single peak shape in the longitudinal direction with respect to the orthogonal direction axis and in the orthogonal direction with respect to the longitudinal direction axis (n is a natural number),
In addition, in the judgment using the above integral contour map, the maximum part of the contour line in the first-order integral is symmetrical in the longitudinal direction of the steel material to be inspected with respect to the orthogonal direction axis, and in the orthogonal direction with respect to the longitudinal direction axis. When it is unimodal,
Each of these values is preset to indicate that the intersection of the longitudinal axis and the orthogonal axis of the steel material to be inspected is a damaged portion of the steel material to be inspected,
Or, the above judgment standard value is
The direction of the magnetic flux within the steel material to be inspected is a direction opposite to the longitudinal direction of the steel material to be inspected, and the magnetic flux density component in a direction approximately perpendicular to the surface of the concrete body, or its differential or integral in the longitudinal direction is the surface of the concrete body. When drawing a contour map with the direction substantially perpendicular to the steel material and moving away from the steel material to be inspected as positive and the opposite direction as negative,
In the judgment using the above differential contour map, the maximum part of the contour line is the first or (1+4n) order of the odd order differentiation, and the minimum part of the contour line is the third order or (3+4n) order of the odd order differentiation. When each of the above-mentioned steel materials to be inspected has a symmetrical unimodal shape in the longitudinal direction with respect to the orthogonal direction axis and in the orthogonal direction with respect to the longitudinal direction axis (n is a natural number),
In addition, in the judgment using the above integral contour map, the minimum part of the contour line in the first-order integral is symmetrical in the longitudinal direction of the steel material to be inspected with respect to the orthogonal direction axis, and in the orthogonal direction with respect to the longitudinal direction axis. When it is unimodal,
A non-destructive testing method characterized in that each of the values is preset to indicate that the intersection of the longitudinal axis and the orthogonal axis of the steel material to be inspected is a damaged portion of the steel material to be inspected. By magnetizing the steel material to be inspected from the outside of the concrete body in which the steel material to be inspected is buried with a magnet, and then measuring the magnetic flux density of the concrete body with a magnetic sensor, it is possible to detect whether or not there is a damaged part of the steel material to be inspected. and a non-destructive testing method for detecting the position,
a magnetization step of arranging the magnetized surface of the magnet close to the surface of the concrete body and then magnetizing the steel material to be inspected along its longitudinal direction by moving it appropriately or without moving it;
At least one magnetic sensor unit including a plurality of magnetic sensors arranged in a row and another magnetic sensor unit are arranged in such a manner that the direction in which each magnetic sensor is arranged is substantially perpendicular to the longitudinal direction of the steel material to be inspected, and After fixing the relative positions of both magnetic sensor units so as to move away from the surface of the concrete object sequentially, the magnetic flux density of the steel material to be inspected can be determined by moving or not moving in the longitudinal direction of the steel material to be inspected. a magnetic flux density measurement step for measuring the
a first processing step of generating raw contour maps of magnetic flux density based on the magnetic flux densities respectively measured by the one magnetic sensor unit and the other magnetic sensor unit in the magnetic flux density measuring step; A flattening process is performed to obtain a flattened contour map by subtracting a linear change in the magnetic flux density in the longitudinal direction, and a smoothing process is performed to obtain a smoothed contour map by smoothing each of the flattened contour maps in the longitudinal direction. a second processing step in which the respective smoothed contour maps are combined by calculation based on the burial depth to obtain a composite smoothed contour map; Perform differentiation processing to obtain differential contour maps by differentiating the first floor or multiple floors in the direction, and calculate each of the differential contour maps based on the buried depth of the steel material to be inspected from the surface of the concrete body. A third processing step is performed to synthesize a composite differential contour map, and an integral process is performed to perform first-order integration in the longitudinal direction on each of the smoothed contour maps to obtain an integral contour map. Of the fourth processing step of synthesizing each of the above-mentioned integral contour maps based on the calculation to obtain a composite integral contour map, at least the above-mentioned first processing step and the above-mentioned second processing step are performed, or at least the above-mentioned a contour map processing step of performing a first processing step and the third processing step, or at least performing the first processing step and the fourth processing step;
Judgment to determine the presence or absence and/or position of damaged parts in the steel material to be inspected by comparing any of the composite smoothed contour map, composite differential contour map, and composite integral contour map with a predetermined criterion value. including the process,
The above judgment standard value is
The direction of the magnetic flux within the steel material to be inspected is the longitudinal direction of the steel material to be inspected, and the magnetic flux density component in a direction substantially orthogonal to the surface of the concrete body, or its differential or integral in the longitudinal direction, is substantially orthogonal to the surface of the concrete body. When drawing a contour map with the direction away from the steel material being inspected as positive and the opposite direction as negative,
In the determination using the composite smoothed contour map, the maximum and minimum parts of the contour lines appear sequentially in the longitudinal direction of the steel to be inspected, and the maximum and minimum parts are orthogonal to each other in the longitudinal direction of the steel to be inspected. When it becomes a bipolar shape that is antisymmetric about the axis and a unimodal shape that is symmetric about the longitudinal axis in the orthogonal direction,
In the judgment using the above composite differential contour map, in the second order or (2+4n) order differential among the even-numbered differentials, the minimum and maximum parts of the contour line appear sequentially in the longitudinal direction of the steel material to be inspected, and the minimum part and When the maximum part has a bipolar shape that is antisymmetrical to the orthogonal direction axis in the longitudinal direction of the steel to be inspected, and a single peak shape that is symmetrical to the longitudinal direction in the orthogonal direction (n is a natural number),
Furthermore, in the 4th or (4+4n) order differential among the even-numbered differentiations, the maximum and minimum parts of the contour line appear sequentially in the longitudinal direction of the steel material to be inspected, and the maximum and minimum parts of the contour line appear in the longitudinal direction of the steel material to be inspected. When it becomes a bipolar shape that is antisymmetric about the orthogonal direction axis, and a unimodal shape that is symmetric about the longitudinal axis in the orthogonal direction (n is a natural number),
Each of these values is preset to indicate that the intersection of the longitudinal axis and the orthogonal axis of the steel material to be inspected is a damaged portion of the steel material to be inspected,
Or, the above judgment standard value is
The direction of the magnetic flux within the steel material to be inspected is a direction opposite to the longitudinal direction of the steel material to be inspected, and the magnetic flux density component in a direction approximately perpendicular to the surface of the concrete body, or its differential or integral in the longitudinal direction is the surface of the concrete body. When drawing a contour map with the direction substantially perpendicular to the steel material and moving away from the steel material to be inspected as positive and the opposite direction as negative,
In the judgment using the composite smoothed contour map, the minimum and maximum parts of the contour line appear sequentially in the longitudinal direction of the steel to be inspected, and the minimum and maximum parts are orthogonal to each other in the longitudinal direction of the steel to be inspected. When it becomes a bipolar shape that is antisymmetric about the axis and a unimodal shape that is symmetric about the longitudinal axis in the orthogonal direction,
In the judgment using the composite differential contour map, the maximum and minimum parts of the contour line appear sequentially in the longitudinal direction of the steel material to be inspected in the second order or (2+4n) order of the even-numbered differentiation, and When the minimum part has a bipolar shape that is antisymmetrical to the orthogonal direction axis in the longitudinal direction of the steel material to be inspected, and a unimodal shape that is symmetrical to the longitudinal direction in the orthogonal direction (n is a natural number),
Furthermore, in the 4th or (4+4n) order differential among the even-numbered differentiations, the minimum and maximum parts of the contour lines appear sequentially in the longitudinal direction of the steel material to be inspected, and the minimum and maximum parts are in the longitudinal direction of the steel material to be inspected. When it becomes a bipolar shape that is antisymmetric about the orthogonal direction axis, and a unimodal shape that is symmetric about the longitudinal axis in the orthogonal direction (n is a natural number),
A non-destructive testing method characterized in that each of the values is preset to indicate that the intersection of the longitudinal axis and the orthogonal axis of the steel material to be inspected is a damaged portion of the steel material to be inspected. By magnetizing the steel material to be inspected from the outside of the concrete body in which the steel material to be inspected is buried with a magnet, and then measuring the magnetic flux density of the concrete body with a magnetic sensor, it is possible to detect whether or not there is a damaged part of the steel material to be inspected. and a non-destructive testing method for detecting the position,
a magnetization step of arranging the magnetized surface of the magnet close to the surface of the concrete body and then magnetizing the steel material to be inspected along its longitudinal direction by moving it appropriately or without moving it;
At least one magnetic sensor unit including a plurality of magnetic sensors arranged in a row and another magnetic sensor unit are arranged in such a manner that the direction in which each magnetic sensor is arranged is substantially perpendicular to the longitudinal direction of the steel material to be inspected, and After fixing the relative positions of both magnetic sensor units so as to move away from the surface of the concrete object sequentially, the magnetic flux density of the steel material to be inspected can be determined by moving or not moving in the longitudinal direction of the steel material to be inspected. a magnetic flux density measurement step for measuring the
a first processing step of generating raw contour maps of magnetic flux density based on the magnetic flux densities respectively measured by the one magnetic sensor unit and the other magnetic sensor unit in the magnetic flux density measuring step; A flattening process is performed to obtain a flattened contour map by subtracting a linear change in the magnetic flux density in the longitudinal direction, and a smoothing process is performed to obtain a smoothed contour map by smoothing each of the flattened contour maps in the longitudinal direction. a second processing step in which the respective smoothed contour maps are combined by calculation based on the burial depth to obtain a composite smoothed contour map; Perform differentiation processing to obtain differential contour maps by differentiating the first floor or multiple floors in the direction, and calculate each of the differential contour maps based on the buried depth of the steel material to be inspected from the surface of the concrete body. A third processing step is performed to synthesize a composite differential contour map, and an integral process is performed to perform first-order integration in the longitudinal direction on each of the smoothed contour maps to obtain an integral contour map. Of the fourth processing step of synthesizing each of the above-mentioned integral contour maps based on the calculation to obtain a composite integral contour map, at least the above-mentioned first processing step and the above-mentioned second processing step are performed, or at least the above-mentioned a contour map processing step of performing a first processing step and the third processing step, or at least performing the first processing step and the fourth processing step;
Judgment to determine the presence or absence and/or position of damaged parts in the steel material to be inspected by comparing any of the composite smoothed contour map, composite differential contour map, and composite integral contour map with a predetermined criterion value. including the process,
The above judgment standard value is
The direction of the magnetic flux within the steel material to be inspected is the longitudinal direction of the steel material to be inspected, and the magnetic flux density component in a direction substantially orthogonal to the surface of the concrete body, or its differential or integral in the longitudinal direction, is substantially orthogonal to the surface of the concrete body. When drawing a contour map with the direction away from the steel material being inspected as positive and the opposite direction as negative,
In the judgment using the above synthetic differential contour map, the minimum part of the contour line is the first or (1+4n) order of the odd-order differentiation, and the maximum part of the contour line is the third-order or (3+4n) order of the odd-order differentiation. , when the longitudinal direction of the steel material to be inspected has a symmetrical single peak shape with respect to the orthogonal direction axis, and the orthogonal direction with respect to the longitudinal direction axis (n is a natural number),
In addition, in the judgment using the above composite integral contour map, the maximum part of the contour line in the first-order integral is symmetrical in the longitudinal direction of the steel material to be inspected with respect to the orthogonal direction axis, and in the orthogonal direction with respect to the longitudinal direction axis. When the shape is unimodal,
Each of these values is preset to indicate that the intersection of the longitudinal axis and the orthogonal axis of the steel material to be inspected is a damaged portion of the steel material to be inspected,
Or, the above judgment standard value is
The direction of the magnetic flux within the steel material to be inspected is a direction opposite to the longitudinal direction of the steel material to be inspected, and the magnetic flux density component in a direction approximately perpendicular to the surface of the concrete body, or its differential or integral in the longitudinal direction is the surface of the concrete body. When drawing a contour map with the direction substantially perpendicular to the steel material and moving away from the steel material to be inspected as positive and the opposite direction as negative,
In the judgment using the above synthetic differential contour map, the maximum part of the contour line is the first or (1+4n) order of the odd-order differentiation, and the minimum part of the contour line is the minimum part of the contour line for the third or (3+4n) order of the odd-order differentiation. , when the longitudinal direction of the steel material to be inspected has a symmetrical single peak shape with respect to the orthogonal direction axis, and the orthogonal direction with respect to the longitudinal direction axis (n is a natural number),
In addition, in the judgment using the above synthetic integral contour map, the minimum part of the contour line in the first-order integral is symmetrical in the longitudinal direction of the steel material to be inspected with respect to the orthogonal direction axis, and in the orthogonal direction with respect to the longitudinal direction axis. When the shape is unimodal,
A non-destructive testing method characterized in that each of the values is preset to indicate that the intersection of the longitudinal axis and the orthogonal axis of the steel material to be inspected is a damaged portion of the steel material to be inspected. In the non-destructive testing method according to claim 3 or 4 ,
The above burial depth is
Each raw contour map is generated based on the magnetic flux densities respectively measured by the one magnetic sensor unit and the other magnetic sensor unit in the magnetic flux density measuring step, and each raw contour map has the longitudinal direction of the magnetic flux density. Each smoothed contour map obtained by longitudinally smoothing each flattened contour map obtained by subtracting linear changes, and each smoothed contour map obtained by subtracting linear changes, and each smoothed contour map obtained by subtracting linear changes, and The above inspection is carried out by calculation based on at least one contour map of each differential contour map obtained by differentiation and each integral contour map obtained by first-order integration in the longitudinal direction for each smoothed contour map. A non-destructive testing method characterized by determining the buried depth of the target steel material. The non-destructive testing method according to claim 1, 2, 3, 4 or 5 ,
In the above judgment step,
Verify the accuracy of the judgment result based on the comparison between the raw contour map, flattened contour map, smoothed contour map, differential contour map, and integral contour map and the above judgment reference value, and determine whether re-judgment is necessary. If it is determined, the existence and/or position of the damaged part of the steel material to be inspected shall be re-determined by comparing the above judgment standard values with another contour map different from the contour map used for the previous judgment. A non-destructive testing method characterized by: By magnetizing the steel material to be inspected from the outside of the concrete body in which the steel material to be inspected is buried with a magnet, and then measuring the magnetic flux density of the concrete body with a magnetic sensor, it is possible to detect whether or not there is a damaged part of the steel material to be inspected. and a non-destructive inspection device for detecting the position,
A magnetizing unit including a magnet that magnetizes the steel material to be inspected along its longitudinal direction by or without moving the magnetized surface as appropriate after arranging it close to the surface of the concrete body;
After arranging a magnetic sensor unit having a plurality of magnetic sensors arranged in a row close to the surface of the concrete body with the direction in which the magnetic sensors are arranged substantially perpendicular to the longitudinal direction of the steel material to be inspected, a magnetic flux density measurement unit that measures the magnetic flux density of the steel material to be inspected by or without moving the steel material in the longitudinal direction;
A raw contour map generation process that generates a contour map of magnetic flux density based on the magnetic flux density measured by the magnetic flux density measurement unit, and a flattened contour map by subtracting a linear change in the longitudinal direction of the magnetic flux density from the raw contour map. a smoothing process to obtain a smoothed contour map, a smoothing process to obtain a smoothed contour map by smoothing the flattened contour map in the longitudinal direction, and a first-order or multiple-order differential in the longitudinal direction for the smoothed contour map. At least the above-mentioned raw contour map generation process and the above-mentioned flattening process. or at least the above raw contour map generation process, the flattening process and the smoothing process, or at least the above raw contour map generation process and the differentiation process, or at least the above raw contour map generation process and a contour map processing unit that performs the flattening process and the integration process;
Compare any one of the flattened contour map, smoothed contour map, differential contour map, and integral contour map with a predetermined criterion value to determine the presence and/or location of damaged parts in the steel material to be inspected. and a determination unit to
The above judgment standard value is
The direction of the magnetic flux within the steel material to be inspected is the longitudinal direction of the steel material to be inspected, and the magnetic flux density component in a direction substantially orthogonal to the surface of the concrete body, or its differential or integral in the longitudinal direction, is substantially orthogonal to the surface of the concrete body. When drawing a contour map with the direction away from the steel material being inspected as positive and the opposite direction as negative,
In the judgment using the flattened contour map or the smoothed contour map, the maximum and minimum parts of the contour line appear sequentially in the longitudinal direction of the steel to be inspected, and the maximum and minimum parts are located in the longitudinal direction of the steel to be inspected. When in the direction it is bipolar, antisymmetrical about the orthogonal axis, and in the orthogonal direction, it is unimodal, symmetrical about the longitudinal axis,
In the judgment using the above differential contour map, in the second order or (2+4n) order differential among the even number of differentiations, the minimum and maximum parts of the contour line appear sequentially in the longitudinal direction of the steel material to be inspected, and the minimum and maximum parts appear sequentially in the longitudinal direction of the steel material to be inspected. When the part is bipolar in the longitudinal direction of the steel to be inspected, which is antisymmetrical to the orthogonal direction axis, and in the orthogonal direction, it is a monomodal shape that is symmetrical to the longitudinal direction (n is a natural number),
Furthermore, in the 4th or (4+4n) order differential among the even-numbered differentiations, the maximum and minimum parts of the contour line appear sequentially in the longitudinal direction of the steel material to be inspected, and the maximum and minimum parts of the contour line appear in the longitudinal direction of the steel material to be inspected. When it becomes a bipolar shape that is antisymmetric about the orthogonal direction axis, and a unimodal shape that is symmetric about the longitudinal axis in the orthogonal direction (n is a natural number),
Each of these values is preset to indicate that the intersection of the longitudinal axis and the orthogonal axis of the steel material to be inspected is a damaged portion of the steel material to be inspected,
Or, the above judgment standard value is
The direction of the magnetic flux within the steel material to be inspected is a direction opposite to the longitudinal direction of the steel material to be inspected, and the magnetic flux density component in a direction approximately perpendicular to the surface of the concrete body, or its differential or integral in the longitudinal direction is the surface of the concrete body. When drawing a contour map with the direction substantially perpendicular to the steel material and moving away from the steel material to be inspected as positive and the opposite direction as negative,
In the judgment using the flattened contour map or the smoothed contour map, the minimum and maximum parts of the contour line appear sequentially in the longitudinal direction of the steel to be inspected, and the minimum and maximum parts are located in the longitudinal direction of the steel to be inspected. When in the direction it is bipolar, antisymmetrical about the orthogonal axis, and in the orthogonal direction, it is unimodal, symmetrical about the longitudinal axis,
In the judgment using the above differential contour map, in the second order or (2+4n) order differential among the even number of differentiations, the maximum and minimum parts of the contour line appear sequentially in the longitudinal direction of the steel material to be inspected, and the maximum and minimum parts appear sequentially in the longitudinal direction of the steel material to be inspected. When the part is bipolar in the longitudinal direction of the steel to be inspected, which is antisymmetrical to the orthogonal direction axis, and in the orthogonal direction, it is a monomodal shape that is symmetrical to the longitudinal direction (n is a natural number),
Furthermore, in the 4th or (4+4n) order differential among the even-numbered differentiations, the minimum and maximum parts of the contour lines appear sequentially in the longitudinal direction of the steel material to be inspected, and the minimum and maximum parts are in the longitudinal direction of the steel material to be inspected. When it becomes a bipolar shape that is antisymmetric about the orthogonal direction axis, and a unimodal shape that is symmetric about the longitudinal axis in the orthogonal direction (n is a natural number),
A non-destructive inspection device characterized in that each of the values is preset to indicate that the intersection of the longitudinal axis and the orthogonal axis of the steel material to be inspected is a damaged portion of the steel material to be inspected. By magnetizing the steel material to be inspected from the outside of the concrete body in which the steel material to be inspected is buried with a magnet, and then measuring the magnetic flux density of the concrete body with a magnetic sensor, it is possible to detect whether or not there is a damaged part of the steel material to be inspected. and a non-destructive inspection device for detecting the position,
A magnetizing unit including a magnet that magnetizes the steel material to be inspected along its longitudinal direction by or without moving the magnetized surface as appropriate after arranging it close to the surface of the concrete body;
After arranging a magnetic sensor unit having a plurality of magnetic sensors arranged in a row close to the surface of the concrete body with the direction in which the magnetic sensors are arranged substantially perpendicular to the longitudinal direction of the steel material to be inspected, a magnetic flux density measurement unit that measures the magnetic flux density of the steel material to be inspected by or without moving the steel material in the longitudinal direction;
A raw contour map generation process that generates a contour map of magnetic flux density based on the magnetic flux density measured by the magnetic flux density measurement unit, and a flattened contour map by subtracting a linear change in the longitudinal direction of the magnetic flux density from the raw contour map. a smoothing process to obtain a smoothed contour map, a smoothing process to obtain a smoothed contour map by smoothing the flattened contour map in the longitudinal direction, and a first-order or multiple-order differential in the longitudinal direction for the smoothed contour map. At least the above-mentioned raw contour map generation process and the above-mentioned flattening process. or at least the above raw contour map generation process, the flattening process and the smoothing process, or at least the above raw contour map generation process and the differentiation process, or at least the above raw contour map generation process and a contour map processing unit that performs the flattening process and the integration process;
Compare any one of the flattened contour map, smoothed contour map, differential contour map, and integral contour map with a predetermined criterion value to determine the presence and/or location of damaged parts in the steel material to be inspected. and a determination unit to
The above judgment standard value is
The direction of the magnetic flux within the steel material to be inspected is the longitudinal direction of the steel material to be inspected, and the magnetic flux density component in a direction substantially orthogonal to the surface of the concrete body, or its differential or integral in the longitudinal direction, is substantially orthogonal to the surface of the concrete body. When drawing a contour map with the direction away from the steel material being inspected as positive and the opposite direction as negative,
In the determination using the above differential contour map, the minimum part of the contour line is the first or (1+4n) order of odd-order differentiation, and the maximum part of the contour line is the third-order or (3+4n) order of odd-order differentiation. When each of the above-mentioned steel materials to be inspected has a symmetrical single peak shape in the longitudinal direction with respect to the orthogonal direction axis and in the orthogonal direction with respect to the longitudinal direction axis (n is a natural number),
In addition, in the judgment using the above integral contour map, the maximum part of the contour line in the first-order integral is symmetrical in the longitudinal direction of the steel material to be inspected with respect to the orthogonal direction axis, and in the orthogonal direction with respect to the longitudinal direction axis. When it is unimodal,
Each of these values is preset to indicate that the intersection of the longitudinal axis and the orthogonal axis of the steel material to be inspected is a damaged portion of the steel material to be inspected,
Or, the above judgment standard value is
The direction of the magnetic flux within the steel material to be inspected is a direction opposite to the longitudinal direction of the steel material to be inspected, and the magnetic flux density component in a direction approximately perpendicular to the surface of the concrete body, or its differential or integral in the longitudinal direction is the surface of the concrete body. When drawing a contour map with the direction substantially perpendicular to the steel material and moving away from the steel material to be inspected as positive and the opposite direction as negative,
In the determination using the above differential contour map, the maximum part of the contour line is the first or (1+4n) order of odd-order differentiation, and the minimum part of the contour line is the third-order or (3+4n) order of odd-order differentiation. When each of the above-mentioned steel materials to be inspected has a symmetrical single peak shape in the longitudinal direction with respect to the orthogonal direction axis and in the orthogonal direction with respect to the longitudinal direction axis (n is a natural number),
In addition, in the judgment using the above integral contour map, the minimum part of the contour line in the first-order integral is symmetrical in the longitudinal direction of the steel material to be inspected with respect to the orthogonal direction axis, and in the orthogonal direction with respect to the longitudinal direction axis. When it is unimodal,
A non-destructive inspection device characterized in that each of the values is preset to indicate that the intersection of the longitudinal axis and the orthogonal axis of the steel material to be inspected is a damaged portion of the steel material to be inspected. By magnetizing the steel material to be inspected from the outside of the concrete body in which the steel material to be inspected is buried with a magnet, and then measuring the magnetic flux density of the concrete body with a magnetic sensor, it is possible to detect whether or not there is a damaged part of the steel material to be inspected. and a non-destructive inspection device for detecting the position,
A magnetizing unit including a magnet that magnetizes the steel material to be inspected along its longitudinal direction by or without moving the magnetized surface as appropriate after arranging it close to the surface of the concrete body;
At least one magnetic sensor unit including a plurality of magnetic sensors arranged in a row and another magnetic sensor unit are arranged in such a manner that the direction in which each magnetic sensor is arranged is substantially perpendicular to the longitudinal direction of the steel material to be inspected, and After fixing the relative positions of both magnetic sensor units so as to move away from the surface of the concrete object sequentially, the magnetic flux density of the steel material to be inspected can be determined by moving or not moving in the longitudinal direction of the steel material to be inspected. a magnetic flux density measurement unit that measures the
a first processing unit that generates respective raw contour maps of magnetic flux density based on magnetic flux densities respectively measured by the first magnetic sensor unit and the other magnetic sensor unit in the magnetic flux density measuring unit; and each of the raw contour maps of the magnetic flux density. A flattening process is performed to obtain a flattened contour map by subtracting a linear change in the magnetic flux density in the longitudinal direction, and a smoothing process is performed to obtain a smoothed contour map by smoothing each of the flattened contour maps in the longitudinal direction. a second processing unit that performs a processing and synthesizes each of the smoothed contour maps by calculation based on the buried depth of the steel material to be inspected from the surface of the concrete body to obtain a composite smoothed contour map; The above smoothed contour maps are differentiated by one or more floors in the longitudinal direction to obtain differential contour maps, and each differential contour map is calculated based on the burial depth. A third processing unit performs integration processing to obtain integral contour maps by performing first-order integration in the longitudinal direction on each of the smoothed contour maps, and calculates the buried depth. A fourth processing unit that combines the respective integral contour maps based on the calculation to obtain a composite integral contour diagram, comprises at least the first processing unit and the second processing unit, or includes at least the first processing unit and the second processing unit, or a contour map processing section comprising a first processing section and the third processing section, or at least the first processing section and the fourth processing section;
Judgment to determine the presence or absence and/or position of damaged parts in the steel material to be inspected by comparing any of the composite smoothed contour map, composite differential contour map, and composite integral contour map with a predetermined criterion value. Equipped with a
The above judgment standard value is
The direction of the magnetic flux within the steel material to be inspected is the longitudinal direction of the steel material to be inspected, and the magnetic flux density component in a direction substantially orthogonal to the surface of the concrete body, or its differential or integral in the longitudinal direction, is substantially orthogonal to the surface of the concrete body. When drawing a contour map with the direction away from the steel material being inspected as positive and the opposite direction as negative,
In the determination using the composite smoothed contour map, the maximum and minimum parts of the contour lines appear sequentially in the longitudinal direction of the steel to be inspected, and the maximum and minimum parts are orthogonal to each other in the longitudinal direction of the steel to be inspected. When it becomes a bipolar shape that is antisymmetric about the axis and a unimodal shape that is symmetric about the longitudinal axis in the orthogonal direction,
In the judgment using the above composite differential contour map, in the second order or (2+4n) order differential among the even-numbered differentials, the minimum and maximum parts of the contour line appear sequentially in the longitudinal direction of the steel material to be inspected, and the minimum part and When the maximum part has a bipolar shape that is antisymmetrical to the orthogonal direction axis in the longitudinal direction of the steel to be inspected, and a single peak shape that is symmetrical to the longitudinal direction in the orthogonal direction (n is a natural number),
Furthermore, in the 4th or (4+4n) order differential among the even-numbered differentiations, the maximum and minimum parts of the contour line appear sequentially in the longitudinal direction of the steel material to be inspected, and the maximum and minimum parts of the contour line appear in the longitudinal direction of the steel material to be inspected. When it becomes a bipolar shape that is antisymmetric about the orthogonal direction axis, and a unimodal shape that is symmetric about the longitudinal axis in the orthogonal direction (n is a natural number),
Each of these values is preset to indicate that the intersection of the longitudinal axis and the orthogonal axis of the steel material to be inspected is a damaged portion of the steel material to be inspected,
Or, the above judgment standard value is
The direction of the magnetic flux within the steel material to be inspected is a direction opposite to the longitudinal direction of the steel material to be inspected, and the magnetic flux density component in a direction approximately perpendicular to the surface of the concrete body, or its differential or integral in the longitudinal direction is the surface of the concrete body. When drawing a contour map with the direction substantially perpendicular to the steel material and moving away from the steel material to be inspected as positive and the opposite direction as negative,
In the judgment using the composite smoothed contour map, the minimum and maximum parts of the contour line appear sequentially in the longitudinal direction of the steel to be inspected, and the minimum and maximum parts are orthogonal to each other in the longitudinal direction of the steel to be inspected. When it becomes a bipolar shape that is antisymmetric about the axis and a unimodal shape that is symmetric about the longitudinal axis in the orthogonal direction,
In the judgment using the composite differential contour map, the maximum and minimum parts of the contour line appear sequentially in the longitudinal direction of the steel material to be inspected in the second order or (2+4n) order of the even-numbered differentiation, and When the minimum part has a bipolar shape that is antisymmetrical to the orthogonal direction axis in the longitudinal direction of the steel material to be inspected, and a unimodal shape that is symmetrical to the longitudinal direction in the orthogonal direction (n is a natural number),
Furthermore, in the 4th or (4+4n) order differential among the even-numbered differentiations, the minimum and maximum parts of the contour lines appear sequentially in the longitudinal direction of the steel material to be inspected, and the minimum and maximum parts are in the longitudinal direction of the steel material to be inspected. When it becomes a bipolar shape that is antisymmetric to the orthogonal axis, and a unimodal shape that is symmetric to the longitudinal axis in the orthogonal direction (n is a natural number),
A non-destructive inspection device characterized in that each of the values is preset to indicate that the intersection of the longitudinal axis and the orthogonal axis of the steel material to be inspected is a damaged portion of the steel material to be inspected. By magnetizing the steel material to be inspected from the outside of the concrete body in which the steel material to be inspected is buried with a magnet, and then measuring the magnetic flux density of the concrete body with a magnetic sensor, it is possible to detect whether or not there is a damaged part of the steel material to be inspected. and a non-destructive inspection device for detecting the position,
A magnetizing unit including a magnet that magnetizes the steel material to be inspected along its longitudinal direction by or without moving the magnetized surface as appropriate after arranging it close to the surface of the concrete body;
At least one magnetic sensor unit including a plurality of magnetic sensors arranged in a row and another magnetic sensor unit are arranged in such a manner that the direction in which each magnetic sensor is arranged is substantially perpendicular to the longitudinal direction of the steel material to be inspected, and After fixing the relative positions of both magnetic sensor units so as to move away from the surface of the concrete object sequentially, the magnetic flux density of the steel material to be inspected can be determined by moving or not moving in the longitudinal direction of the steel material to be inspected. a magnetic flux density measurement unit that measures the
a first processing unit that generates respective raw contour maps of magnetic flux density based on magnetic flux densities respectively measured by the first magnetic sensor unit and the other magnetic sensor unit in the magnetic flux density measuring unit; and each of the raw contour maps of the magnetic flux density. A flattening process is performed to obtain a flattened contour map by subtracting a linear change in the magnetic flux density in the longitudinal direction, and a smoothing process is performed to obtain a smoothed contour map by smoothing each of the flattened contour maps in the longitudinal direction. a second processing unit that performs a processing and synthesizes each of the smoothed contour maps by calculation based on the buried depth of the steel material to be inspected from the surface of the concrete body to obtain a composite smoothed contour map; The above smoothed contour maps are differentiated by one or more floors in the longitudinal direction to obtain differential contour maps, and each differential contour map is calculated based on the burial depth. A third processing unit performs integration processing to obtain integral contour maps by performing first-order integration in the longitudinal direction on each of the smoothed contour maps, and calculates the buried depth. A fourth processing unit that combines the respective integral contour maps based on the calculation to obtain a composite integral contour diagram, comprises at least the first processing unit and the second processing unit, or includes at least the first processing unit and the second processing unit, or a contour map processing section comprising a first processing section and the third processing section, or at least the first processing section and the fourth processing section;
Judgment to determine the presence or absence and/or position of damaged parts in the steel material to be inspected by comparing any of the composite smoothed contour map, composite differential contour map, and composite integral contour map with a predetermined criterion value. Equipped with a
The above judgment standard value is
The direction of the magnetic flux within the steel material to be inspected is the longitudinal direction of the steel material to be inspected, and the magnetic flux density component in a direction substantially orthogonal to the surface of the concrete body, or its differential or integral in the longitudinal direction, is substantially orthogonal to the surface of the concrete body. When drawing a contour map with the direction away from the steel material being inspected as positive and the opposite direction as negative,
In the judgment using the above synthetic differential contour map, the minimum part of the contour line is the first or (1+4n) order of the odd-order differentiation, and the maximum part of the contour line is the third-order or (3+4n) order of the odd-order differentiation. , when the longitudinal direction of the steel material to be inspected has a symmetrical single peak shape with respect to the orthogonal direction axis, and the orthogonal direction with respect to the longitudinal direction axis (n is a natural number),
In addition, in the judgment using the above composite integral contour map, the maximum part of the contour line in the first-order integral is symmetrical in the longitudinal direction of the steel material to be inspected with respect to the orthogonal direction axis, and in the orthogonal direction with respect to the longitudinal direction axis. When the shape is unimodal,
Each of these values is preset to indicate that the intersection of the longitudinal axis and the orthogonal axis of the steel material to be inspected is a damaged portion of the steel material to be inspected,
Or, the above judgment standard value is
The direction of the magnetic flux within the steel material to be inspected is a direction opposite to the longitudinal direction of the steel material to be inspected, and the magnetic flux density component in a direction approximately perpendicular to the surface of the concrete body, or its differential or integral in the longitudinal direction is the surface of the concrete body. When drawing a contour map with the direction substantially perpendicular to the steel material and moving away from the steel material to be inspected as positive and the opposite direction as negative,
In the judgment using the above synthetic differential contour map, the maximum part of the contour line is the first or (1+4n) order of the odd-order differentiation, and the minimum part of the contour line is the minimum part of the contour line for the third or (3+4n) order of the odd-order differentiation. , when the longitudinal direction of the steel material to be inspected has a symmetrical single peak shape with respect to the orthogonal direction axis, and the orthogonal direction with respect to the longitudinal direction axis (n is a natural number),
In addition, in the judgment using the above synthetic integral contour map, the minimum part of the contour line in the first-order integral is symmetrical in the longitudinal direction of the steel material to be inspected with respect to the orthogonal direction axis, and in the orthogonal direction with respect to the longitudinal direction axis. When the shape is unimodal,
A non-destructive inspection device characterized in that each of the values is preset to indicate that the intersection of the longitudinal axis and the orthogonal axis of the steel material to be inspected is a damaged portion of the steel material to be inspected. The nondestructive testing device according to claim 9 or 10 ,
The above burial depth is
Each raw contour map is generated based on the magnetic flux densities respectively measured by the one magnetic sensor unit and the other magnetic sensor unit in the magnetic flux density measuring unit, and each raw contour map has a longitudinal direction of the magnetic flux density. Each smoothed contour map obtained by longitudinally smoothing each flattened contour map obtained by subtracting linear changes, and each smoothed contour map obtained by subtracting linear changes, and each smoothed contour map obtained by subtracting linear changes, and Calculation based on at least one contour map of each differential contour map obtained by differentiation and each integral contour map obtained by performing first-order integration in the longitudinal direction on each of the above-mentioned smoothed contour maps. A non-destructive testing device featuring: The non-destructive testing device according to claim 7, 8, 9, 10 or 11 ,
The determination unit verifies the accuracy of the determination result based on the comparison between the raw contour map, flattened contour map, smoothed contour map, differential contour map, and integral contour map and the determination reference value, and again If it is determined that it is necessary to make a judgment, the existence and/or location of damaged parts of the steel material to be inspected is determined by comparing the above judgment standard values with another contour map different from the contour map used for the previous judgment. A non-destructive inspection device characterized by being configured to redetermine.

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