JP4700475B2 - Elastic constant measuring device, elastic constant measuring method, program, and computer-readable storage medium - Google Patents

Description

  The present invention relates to an elastic constant measuring apparatus for measuring an elastic constant of a polycrystalline body using ultrasonic waves, an elastic constant measuring method, a program for causing a computer to execute the elastic constant measuring method, and a computer-readable computer storing the program The present invention relates to a storage medium.

  Conventionally, as a method for measuring an elastic constant in a material having a texture such as a steel plate (hereinafter also referred to as a polycrystal), for example, electromagnetic ultrasonic waves, which is a kind of non-contact method in which a probe does not contact an object to be measured Measurement using the method is considered.

  In the following Non-Patent Document 1, in a metal plate (measurement plate) created by rolling, longitudinal wave ultrasonic waves propagated in the plate thickness direction generated using the electromagnetic ultrasonic method, the longitudinal direction of the measurement plate (rolling) Direction), transverse ultrasonic waves polarized in the width direction of the plate to be measured, and two types of surface ultrasonic waves that are displaced parallel to the surface of the plate to be measured (hereinafter, this measurement target) A surface ultrasonic wave that is displaced parallel to the surface of the plate is referred to as a “surface SH wave”, and the acoustic velocity of each ultrasonic wave is measured, and the elastic constant of the polycrystal is calculated based on the measured sound velocity values. Is.

  In the following Non-Patent Document 2, the speed of sound in a plurality of surface ultrasonic waves including a surface SH wave generated on a measurement target plate using an electromagnetic ultrasonic method is measured, and based on each measured sound speed value, An elastic constant is calculated.

K. Kawashima, JASA, Vol. 87, no. 2, 1990, p. 681-690 H. Hirao etc. , “Texture of polycrystallin metallized by ultrasonic velocity measurement”, J. et al. Acoustic. Soc. Am. 81 (5), may, 1987, p. 1434-1440

  However, for example, in a measurement method using laser ultrasonic waves, which is another type of non-contact method, surface SH waves that are displaced parallel to the surface of the measurement target plate are generated on the surface of the measurement target plate. Is difficult in principle, it is difficult to measure the elastic constant of the polycrystalline body using the method described in Non-Patent Document 1 and Non-Patent Document 2 described above. In general, the measurement method using laser ultrasonic waves can take a larger distance between the measuring element and the measurement target plate than the measurement method using electromagnetic ultrasonic waves, and when used in the manufacturing process, It is known to be more suitable. That is, recently, it has been strongly desired to establish a method for measuring the elastic constant of a polycrystal without using surface SH waves.

  The present invention has been made in view of the above-described problems, and is capable of measuring an elastic constant of a polycrystalline body without using a surface SH wave without contact with a measurement target plate and having a large separation distance. The purpose is to do.

The elastic constant measuring apparatus of the present invention includes an ultrasonic wave generating means for generating ultrasonic waves inside and on the surface of the measurement plate, and ultrasonic waves generated inside the measurement plate in the longitudinal direction of the measurement plate. Polarized first transverse wave ultrasonic wave, ultrasonic wave generated inside the measurement target plate and polarized in the width direction of the measurement target plate, generated inside the measurement target plate Longitudinal ultrasonic waves propagated in the plate thickness direction of the plate to be measured and surface ultrasonic waves generated on the surface of the plate to be measured and displaced in the plate thickness direction. Ultrasonic detection means for detecting an ultrasonic wave, first sound velocity calculation means for calculating the sound velocity of the first transverse wave ultrasonic wave detected by the ultrasonic wave detection means as a first sound velocity, and detection by the ultrasonic wave detection means Second sound velocity calculating means for calculating the sound velocity of the second transverse wave ultrasonic wave as the second sound velocity. , The third sound speed calculating means for calculating the sound speed of the longitudinal ultrasonic wave detected by the ultrasonic detecting means as the third sound speed, and the sound speed of the surface ultrasonic wave displaced in the plate thickness direction detected by the ultrasonic detecting means. A fourth sound speed calculating means for calculating the sound speed as a fourth sound speed, and ultrasonic waves generated inside the measured board based on the first sound speed, the second sound speed, the third sound speed, and the fourth sound speed. An elastic constant calculating means for calculating an elastic constant of the polycrystalline body constituting the measurement plate using a predetermined calculation formula without using surface ultrasonic waves that are displaced parallel to the surface of the measurement plate. Have

The elastic constant measuring method of the present invention includes an ultrasonic wave generating step for generating ultrasonic waves inside and on the surface of the measurement target plate, and ultrasonic waves generated inside the measurement target plate in the longitudinal direction of the measurement target plate. Polarized first transverse wave ultrasonic wave, ultrasonic wave generated inside the measurement target plate and polarized in the width direction of the measurement target plate, generated inside the measurement target plate Longitudinal ultrasonic waves propagated in the plate thickness direction of the plate to be measured and surface ultrasonic waves generated on the surface of the plate to be measured and displaced in the plate thickness direction. Ultrasonic wave detecting step for detecting ultrasonic waves, a first sound velocity calculating step for calculating the sound velocity of the first transverse wave ultrasonic wave detected in the ultrasonic wave detecting step as a first sound velocity, and detecting in the ultrasonic wave detecting step Calculate the sound velocity of the second transverse wave ultrasonic wave as the second sound velocity A second sound velocity calculating step, a third sound velocity calculating step for calculating a sound velocity of the longitudinal ultrasonic wave detected in the ultrasonic wave detecting step as a third sound velocity, and a thickness direction detected in the ultrasonic wave detecting step. Based on the first sound speed, the second sound speed, the third sound speed, and the fourth sound speed, a fourth sound speed calculating step for calculating the sound speed of the surface ultrasonic wave to be displaced as the fourth sound speed, and the inside of the measurement target plate The elastic constants of the polycrystals constituting the plate to be measured are determined using a predetermined calculation formula without using the surface ultrasonic waves generated parallel to the surface of the plate to be measured. And calculating an elastic constant.

The program of the present invention includes an ultrasonic wave generation step for generating ultrasonic waves inside and on the surface of the measurement plate, and an ultrasonic wave generated inside the measurement plate and polarized in the longitudinal direction of the measurement plate. The first transverse wave ultrasonic wave, the ultrasonic wave generated inside the measurement target plate, the second transverse wave ultrasonic wave polarized in the width direction of the measurement target plate, and the ultrasonic wave generated inside the measurement target plate The longitudinal ultrasonic wave propagated in the plate thickness direction of the plate to be measured and the ultrasonic waves generated on the surface of the plate to be measured and displaced in the plate thickness direction are ultrasonic waves. An ultrasonic detection step to detect; a first sound velocity calculation step to calculate the sound velocity of the first transverse wave ultrasonic wave detected in the ultrasonic wave detection step as a first sound velocity; and the second sound wave detected in the ultrasonic wave detection step. To calculate the sound velocity of the transverse wave ultrasonic wave as the second sound velocity. A sound velocity calculating step, a third sound velocity calculating step for calculating a sound velocity of the longitudinal ultrasonic wave detected in the ultrasonic wave detecting step as a third sound velocity, and a surface displaced in the plate thickness direction detected in the ultrasonic wave detecting step. Based on the first sound speed, the second sound speed, the third sound speed, and the fourth sound speed, a fourth sound speed calculation step that calculates the sound speed of the ultrasonic wave as the fourth sound speed, and generated inside the measured board. Elasticity that calculates the elastic constants of the polycrystals constituting the measurement plate using a predetermined formula without using ultrasonic waves that are displaced parallel to the surface of the measurement plate. The constant calculation step is for causing the computer to execute.

  The computer-readable storage medium of the present invention stores the program in a computer-readable manner.

  According to the present invention, the elastic constant of a polycrystal can be measured without using a surface SH wave without contact with the plate to be measured.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic configuration diagram of an elastic constant measuring apparatus according to an embodiment of the present invention.
As shown in FIG. 1, the elastic constant measuring apparatus of the present embodiment includes an ultrasonic generation laser 10, an ultrasonic detection laser 20, a head unit 30, an interferometer (frequency change detection means) 50, an optical A detector 60 and an arithmetic processing unit (first to fourth sound speed calculating means and elastic constant calculating means) 70 are provided. In addition, the elastic constant measuring apparatus is provided with optical fibers 91a, 91b and 91c, a condensing lens 92, and the like as optical components.

The ultrasonic wave generation laser 10 is for generating ultrasonic waves inside and on the surface of the measurement target plate 101. As the ultrasonic wave generation laser 10, for example, a high energy pulse laser such as a YAG laser or a CO ₂ laser is used. The laser beam emitted from the ultrasonic wave generation laser 10 is guided to the head unit 30 via the optical fiber 91a.

  The ultrasonic detection laser 20 detects the ultrasonic wave generated inside and on the surface of the measurement target plate 101 by irradiation of the laser beam from the ultrasonic generation laser 10 and propagating through the inside and the surface of the measurement target plate 101. Is for. As the ultrasonic detection laser 20, a laser that emits a single-frequency laser beam is used. The laser beam emitted from the ultrasonic detection laser 20 is guided to the head unit 30 via the optical fiber 91b.

  As shown in FIGS. 2 and 3, the head unit 30 includes an ultrasonic wave generation unit 31 and a laser beam acquisition unit 41. The ultrasonic generator 31 includes a cylindrical lens 35 and a rotation mechanism (not shown) of the cylindrical lens 35.

  The laser beam guided to the ultrasonic wave generation unit 31 by the optical fiber 91 a is incident on the cylindrical lens 35. The cylindrical lens 35 condenses the laser beam from the ultrasonic generation laser 10 in a line shape and irradiates the surface of the measurement target plate 101 as a line focus beam.

  In this embodiment, as shown in FIG. 2, when the orientation of the cylindrical lens 35 is arranged in parallel to the width direction of the measurement target plate 101, it is parallel to the width direction of the measurement target plate 101 ( In other words, a line focus beam L11 (perpendicular to the longitudinal direction of the measurement target plate 101) is irradiated on the surface of the measurement target plate 101. As shown in FIG. 3, when the orientation of the cylindrical lens 35 is arranged in parallel to the longitudinal direction of the measurement target plate 101, it is parallel to the longitudinal direction of the measurement target plate 101 (in other words, A line focus beam L12 (perpendicular to the width direction of the measurement target plate 101) is irradiated on the surface of the measurement target plate 101. Here, the longitudinal direction of the plate 101 to be measured corresponds to the rolling direction when the plate 101 to be measured is a steel plate and in a rolling process.

As shown in FIG. 2, when the line focus beam L <b> 11 is irradiated from the ultrasonic wave generation unit 31, the first polarized wave in the longitudinal direction of the measurement target plate 101 at an angle α in the measurement target plate 101. The transverse ultrasonic wave W _S1 and the longitudinal wave ultrasonic wave W _T1 propagated in the plate thickness direction of the measurement target plate 101 are generated, and the surface ultrasonic wave which is displaced in the plate thickness direction and propagates in the longitudinal direction on the surface of the measurement target plate 101. W _H1 is generated. Further, as shown in FIG. 3, when the line focus beam L12 is irradiated from the ultrasonic wave generation unit 31, the first polarized wave is polarized at an angle β in the width direction of the measurement target plate 101 inside the measurement target plate 101. 2 transverse wave ultrasonic waves W _S2 and longitudinal wave ultrasonic waves W _T2 propagated in the plate thickness direction of the plate 101 to be measured are generated, and the surface 101 of the plate to be measured is displaced 101 in the plate thickness direction and propagates in the width direction. Surface ultrasonic wave W _H2 is generated.

  The direction of the cylindrical lens 35 can be arbitrarily changed in a plane parallel to the surface of the measurement target plate 101 by a rotation mechanism (not shown) of the cylindrical lens 35. The direction of the cylindrical lens 35 shown in FIG. 3 is rotated by 90 ° with respect to the direction of the cylindrical lens 35 shown in FIG. The rotation mechanism of the cylindrical lens 35 is controlled by, for example, the arithmetic processing unit 70.

Note that when the surface of the measurement target plate 101 is irradiated with a point-like laser beam, ultrasonic waves traveling in various directions with respect to the surface of the measurement target plate 101 are generated. Naturally, these ultrasonic waves include ultrasonic waves such as the first transverse wave ultrasonic wave W _S1 and the second transverse wave ultrasonic wave W _S2 described above. It is difficult to accurately detect ultrasonic waves such as the transverse wave ultrasonic wave W _S1 and the second transverse wave ultrasonic wave W _S2 . For this reason, in the present embodiment, the first transverse wave ultrasonic wave W _S1 etc. and the second transverse wave ultrasonic wave W _S2 etc. are generated independently by using the line focus beam and changing the direction of the line. ing.

  The laser beam acquisition unit 41 is a laser emitted from the ultrasonic detection laser 20 at a predetermined position on the surface of the measurement target plate 101 at a predetermined distance from the position irradiated with the line focus beam by the ultrasonic wave generation unit 31. While guiding the beam L20, the laser beam L20 reflected at the predetermined position is acquired.

  Specifically, in the present embodiment, as illustrated in FIG. 2, when the line focus beam L11 is irradiated from the ultrasonic wave generation unit 31, the laser beam acquisition unit 41 is positioned at which the line focus beam L11 is irradiated. The laser beam L20 emitted from the ultrasonic detection laser 20 is guided to a predetermined position P1 at a predetermined distance from the laser beam L20, and the laser beam L20 reflected at the predetermined position P1 is acquired. As shown in FIG. 3, when the line focus beam L12 is irradiated from the ultrasonic wave generation unit 31, the laser beam acquisition unit 41 keeps a predetermined distance from the position irradiated with the line focus beam L12. The laser beam L20 emitted from the ultrasonic detection laser 20 is guided to the predetermined position P2, and the laser beam L20 reflected at the predetermined position P2 is acquired.

  The laser beam acquisition unit 41 includes condensing lenses 45 a and 45 b and a half mirror 46. Further, the laser beam acquisition unit 41 is integrally formed and can move along the longitudinal direction and the width direction of the measurement target plate 101. Then, the laser beam L20 guided from the ultrasonic detection laser 20 to the laser beam acquisition unit 41 by the optical fiber 91b is condensed by the condenser lens 45a, passes through the half mirror 46, and then the surface of the measurement target plate 101. The predetermined position is irradiated.

  Further, in the present embodiment, the laser beam acquisition unit 41 has a laser beam on a straight line that intersects the plane of the line-to-be-measured plate 101 with a plane that passes through the approximate center point of the line focus beam L11 (or L12) and is orthogonal to the line. L20 is to be led. That is, a predetermined position for irradiating the laser beam L20 on the straight line and acquiring the laser beam L20 is set.

  For example, at the end point of the line focus beam L11 in FIG. 2, the situation is the same as when the point laser beam is irradiated, and ultrasonic waves are generated in various directions. For this reason, ultrasonic waves generated in various directions are propagated on a straight line that intersects the plane of the line focus beam L11 passing through the end point of the line focus beam L11 and the surface of the plate 101 to be measured. It is not possible to accurately detect the ultrasonic wave propagated to. On the other hand, at the approximate center point of the line focus beam L11 (or L12), only the ultrasonic wave propagated in the predetermined direction described above is generated, so that it passes through the approximate center point of the line focus beam L11 (or L12) and enters the line. By setting the predetermined position on a straight line where a plane orthogonal to the surface of the measurement target plate 101 intersects, the ultrasonic wave propagated in a predetermined direction can be accurately detected.

Since the surface of the measurement target plate 101 is a rough surface, the laser beam L20 is scattered almost isotropically on the surface of the measurement target plate 101. At this time, for example, the first transverse wave ultrasonic wave W _S1 and the longitudinal wave ultrasonic wave W _T1 that have propagated through the measurement target plate 101 and the surface of the measurement target plate 101 are propagated to the predetermined position P1 shown in FIG. When each ultrasonic wave of the surface ultrasonic wave _WH1 displaced in the plate thickness direction reaches, the predetermined position vibrates ultrasonically. As a result, the laser beam L20 scattered at a predetermined position on the surface of the measurement target plate 101 undergoes a Doppler shift caused by ultrasonic vibration of the surface of the measurement target plate 101, and the frequency changes. Note that the first transverse wave ultrasonic wave W _S1 , the longitudinal wave ultrasonic wave W _T1, and the surface ultrasonic wave W _H1 displaced in the plate thickness direction have different times to reach the predetermined position P1, and therefore, the ultrasonic waves at the predetermined position are different. By detecting a change in the frequency of the laser beam L20 caused by vibration, it is possible to detect each ultrasonic wave separately. Also, in the case of the predetermined position P2 shown in FIG. 3, the same discussion as in the case of the predetermined position P1 shown in FIG. 2 can be applied.

  A part of the laser beam L20 scattered at a predetermined position on the surface of the measurement target plate 101 is reflected by the half mirror 46, collected by the condenser lens 45b, and then enters the optical fiber 91c. The optical fiber 91c guides the laser beam L20 to the interferometer 50. The laser beam L20 emitted from the optical fiber 91c is collected by the condenser lens 92 and then enters the interferometer 50.

As the interferometer 50, for example, a Fabry-Perot interferometer is used. The Fabry-Perot interferometer 50 is based on the laser beam L20 acquired by the laser beam acquisition unit 41, the first transverse wave ultrasonic wave W _S1 , the second transverse wave ultrasonic wave W _S2 , the longitudinal wave ultrasonic wave W _T1 , W. _T2, and caused due to the vibration of each ultrasonic surface ultrasonic W _H1, W _H2 displaced in the thickness direction, which detects the change in frequency with respect to the laser beam L20 which is the irradiated, facing each other It has two reflecting mirrors. The two reflecting mirrors constitute a resonator, and function as a band-pass filter by multiple reflection of the laser beam L20 between the two reflecting mirrors. By adjusting the distance between the two reflecting mirrors, the frequency of the light transmitted through the resonator can be adjusted.

Here, a resonance curve in the Fabry-Perot interferometer 50 will be described.
FIG. 4 is a diagram illustrating an example of a resonance curve in the Fabry-Perot interferometer 50.
In FIG. 4, the horizontal axis indicates the frequency f of the incident light, and the vertical axis indicates the output from the Fabry-Perot interferometer 50, that is, the intensity I of the light transmitted through the Fabry-Perot interferometer 50. As can be seen from FIG. 4, the transmitted light intensity I shows a sharp peak at a specific frequency, but rapidly decreases before and after the peak. The frequency showing this peak can be changed by adjusting the distance between the reflecting mirrors of the Fabry-Perot interferometer 50. Therefore, if the distance between the reflecting mirrors is adjusted so that the frequency at the point (resonance curve operating point) A at which the slope of the curve shown in FIG. 4 is maximum coincides with the oscillation frequency of the laser beam L20. Can be converted into a relatively large change in transmitted light intensity ± ΔI. As a result, the Fabry-Perot interferometer 50 receives the Doppler shift caused by the ultrasonic vibration of the surface of the measurement target plate 101, and when the laser beam L20 whose frequency is changed is input, the change in the frequency is transmitted. Output as intensity change.

  The transmitted light intensity output from the Fabry-Perot interferometer 50 is sent to the photodetector 60. The photodetector 60 converts transmitted light intensity into an electric signal. Thereby, the ultrasonic vibration is finally captured as an electrical signal. A signal from the photodetector 60 is sent to the arithmetic processing unit 70 and stored as waveform data. Here, the laser beam acquisition unit 41, the optical fiber 91c, the condensing lens 92, the Fabry-Perot interferometer (frequency change detection unit) 50 and the photodetector 60 of the head unit 30 are the “ultrasonic detection unit” of the present embodiment. Is configured.

FIG. 5 is a block diagram showing a schematic configuration of the arithmetic processing unit 70 in the elastic constant measuring apparatus.
In FIG. 5, the head drive control unit 71 receives a control command (hereinafter, this control command is referred to as “elastic constant measurement command”) for measuring the elastic constant of the polycrystalline body constituting the measurement target plate 101 from the user. In this case, the head unit 30 is driven and controlled to a desired state. Specifically, when the head drive control unit 71 receives the elastic constant measurement command, for example, first, the ultrasonic wave generation unit 31 and the laser beam acquisition unit 41 of the head unit 30 are in the state illustrated in FIG. Thus, the drive control is performed to generate the first transverse wave ultrasonic wave W _S1 , the longitudinal wave ultrasonic wave W _T1, and the surface ultrasonic wave W _H1 displaced in the plate thickness direction on the measurement target plate 101. Thereafter, drive control is performed so that the ultrasonic wave generation unit 31 and the laser beam acquisition unit 41 of the head unit 30 are in the state illustrated in FIG. 3, and the second transverse wave ultrasonic wave W _S2 , Wave ultrasonic waves W _T2 and surface ultrasonic waves W _H2 displaced in the plate thickness direction are generated.

The waveform data storage unit 72 is displaced from the first transverse wave ultrasonic wave W _S1 , the second transverse wave ultrasonic wave W _S2 , the longitudinal wave ultrasonic waves W _T1 and W _T2 , and the thickness direction outputted from the photodetector 60. Signals in the ultrasonic waves of the surface ultrasonic waves W _H1 and W _H2 are stored as waveform data.

  Based on the waveform data representing the frequency change of the laser beam L20 in each ultrasonic wave detected by the Fabry-Perot interferometer 50, the sound speed calculation unit 73 stores the ultrasonic wave. The propagation time propagated through the inside or the surface of the measurement target plate 101 is obtained, and the sound speed of each ultrasonic wave is calculated based on the obtained propagation time. The sound speed calculation unit 73 includes a first sound speed calculation unit 731, a second sound speed calculation unit 732, a third sound speed calculation unit 733, and a fourth sound speed calculation unit 734.

The first sound velocity calculation unit 731 is based on waveform data representing the frequency change of the laser beam L20 in the first transverse wave ultrasonic wave W _S1 detected by the Fabry-Perot interferometer 50, stored in the waveform data storage unit 72. Thus, the propagation time during which the first transverse wave ultrasonic wave W _S1 propagates through the measurement target plate 101 is obtained, and the sound speed of the first transverse wave ultrasonic wave W _S1 is determined based on the obtained propagation time. Calculated as _S1 .

The second sound speed calculation unit 732 is based on the waveform data representing the frequency change of the laser beam L20 in the second transverse wave ultrasonic wave W _S2 detected by the Fabry-Perot interferometer 50, stored in the waveform data storage unit 72. Te, the second transverse ultrasonic wave W _S2 is determined propagation time having propagated inside of the measurement plate 101, the determined based on the propagation time of the acoustic velocity of the second transverse ultrasonic wave W _S2 second acoustic velocity V Calculated as _S2 .

The third sound speed calculator 733 stores the frequency of the laser beam L20 in the longitudinal wave W _T1 (or longitudinal wave W _T2 ) detected by the Fabry-Perot interferometer 50 and stored in the waveform data storage 72. Based on the waveform data representing the change, the propagation time in which the longitudinal wave ultrasonic wave W _T1 (or longitudinal wave ultrasonic wave W _T2 ) propagates through the measurement target plate 101 is obtained, and based on the obtained propagation time, The sound speed of the wave ultrasonic wave W _T1 (or longitudinal wave ultrasonic wave W _T2 ) is calculated as the third sound speed V _T.

The fourth sound velocity calculation unit 734 stores the surface ultrasonic wave W _H1 (or the surface supersonic wave displaced in the plate thickness direction) that is stored in the waveform data storage unit 72 and is detected by the Fabry-Perot interferometer 50 in the plate thickness direction. based on the waveform data representing a frequency change of the laser beam L20 in waves W _H2), the thickness direction surface displaced ultrasonic W _H1 (or ultrasonic W _H2 surface displaced in the thickness direction) of the measurement plate 101 The propagation speed of propagation on the surface of the surface is obtained, and the sound velocity of the surface ultrasonic wave W _H1 (or surface ultrasonic wave W _H2 displaced in the plate thickness direction) displaced in the plate thickness direction based on the obtained propagation time is set to the fourth sound velocity. Calculated as V _H.

The elastic constant calculation unit 74 includes a first sound speed V _S1 calculated by the first sound speed calculation unit 731, a second sound speed V _S2 calculated by the second sound speed calculation unit 732, and a first sound speed V _s2 calculated by the third sound speed calculation unit 733. Based on the three sound speeds V _T and the fourth sound speed V _H calculated by the fourth sound speed calculation unit 734, the elastic constant of the polycrystal constituting the measurement target plate 101 is calculated using a predetermined calculation formula. The elastic constant of the polycrystalline body calculated by the elastic constant calculation unit 74 is measured from the elastic constant calculation unit 74 for various measurements such as Young's modulus measurement, yield strength measurement, or tensile strength measurement of the plate 101 to be measured. Sent to the device.

Next, a measuring method in the elastic constant measuring device will be described.
FIG. 6 is a flowchart showing an example of an elastic constant measuring method performed by the elastic constant measuring apparatus according to the embodiment of the present invention.

  First, in step S <b> 1, the head drive control unit 71 determines whether or not an elastic constant measurement command for measuring the elastic constant of the polycrystalline body constituting the measurement target plate 101 has been received from the user. If it is determined that an elastic constant measurement command has been received, the process proceeds to step S2. On the other hand, as a result of the determination in step S2, if the elastic constant measurement command has not been received, the process of step S1 is repeated until the elastic constant measurement command is received.

Subsequently, in step S2, the head drive control unit 71 performs drive control so that the ultrasonic generation unit 31 and the laser beam acquisition unit 41 of the head unit 30 are in the state shown in FIG. The line focus beam L11 is emitted from the unit 31. By irradiation with the line focus beam L11, the first transverse wave ultrasonic wave W _S1 polarized at an angle α in the longitudinal direction of the measurement target plate 101 and the thickness direction of the measurement target plate 101 are propagated inside the measurement target plate 101. The generated longitudinal wave ultrasonic wave W _T1 is generated, and the surface ultrasonic wave W _{H1 that} is displaced in the plate thickness direction is generated on the surface of the measurement target plate 101.

Subsequently, in step S3, the ultrasonic detection means detects the first transverse wave ultrasonic wave W _S1 , the longitudinal wave ultrasonic wave W _T1, and the surface ultrasonic wave W _H1 that is displaced in the plate thickness direction generated on the measurement target plate 101. .

Hereinafter, a specific ultrasonic detection method in step S3 will be described.
First, in the laser beam acquisition unit 41, the ultrasonic detection laser 20 moves to a predetermined position P1 on the surface of the measurement target plate 101 at a predetermined distance from the position irradiated with the line focus beam L11 by the ultrasonic wave generation unit 31. The emitted laser beam L20 is guided and the laser beam L20 reflected at the predetermined position P1 is acquired. Next, in the Fabry-Perot interferometer (frequency change detection means) 50, based on the laser beam L20 acquired by the laser beam acquisition unit 41, the first transverse ultrasonic wave W _S1 generated on the measurement target plate 101, the longitudinal wave A change in frequency with respect to the irradiated laser beam L20 caused by the vibration of each of the ultrasonic wave W _T1 and the surface ultrasonic wave W _H1 displaced in the plate thickness direction is output as a change in transmitted light intensity. Thereafter, in the photodetector 60, the transmitted light intensity output from the Fabry-Perot interferometer 50 is converted into an electrical signal and output to the arithmetic processing unit 70.

Subsequently, in step S4, the arithmetic processing unit 70 outputs the first transverse wave ultrasonic wave W _S1 , the longitudinal wave ultrasonic wave W _T1, and the surface ultrasonic wave W displaced in the plate thickness direction output from the photodetector 60 in step S3. _The electrical signal related to each ultrasonic wave of _H1 is stored in the waveform data storage unit 72 as waveform data representing the frequency change of the laser beam L20 in each ultrasonic wave.

Subsequently, in step S5, the head drive control unit 71 performs drive control so that the ultrasonic wave generation unit 31 and the laser beam acquisition unit 41 of the head unit 30 are in the state illustrated in FIG. The line focus beam L12 is irradiated from the unit 31. By irradiation with the line focus beam L12, the second transverse wave ultrasonic wave W _S2 polarized in the width direction of the measurement target plate 101 at an angle β and propagates in the thickness direction of the measurement target plate 101 inside the measurement target plate 101. The generated longitudinal wave ultrasonic wave W _T2 is generated, and the surface ultrasonic wave W _{H2 that} is displaced in the thickness direction is generated on the surface of the measurement target plate 101.

Subsequently, in step S6, the ultrasonic wave detecting means detects the second transverse wave ultrasonic wave W _S2 , the longitudinal wave ultrasonic wave W _T2, and the surface ultrasonic wave W _H2 displaced in the plate thickness direction generated on the measurement target plate 101. .

Hereinafter, a specific ultrasonic detection method in step S6 will be described.
First, in the laser beam acquisition unit 41, the ultrasonic detection laser 20 moves to a predetermined position P2 on the surface of the measurement target plate 101 at a predetermined distance from the position irradiated with the line focus beam L12 by the ultrasonic wave generation unit 31. The emitted laser beam L20 is guided and the laser beam L20 reflected at the predetermined position P2 is acquired. Next, in the Fabry-Perot interferometer (frequency change detection means) 50, the second transverse wave ultrasonic wave W _S2 generated on the measurement target plate 101 based on the laser beam L 20 acquired by the laser beam acquisition unit 41, the longitudinal wave A change in frequency with respect to the irradiated laser beam L20 caused by the vibration of each of the ultrasonic wave W _T2 and the surface ultrasonic wave W _H2 displaced in the plate thickness direction is output as a change in transmitted light intensity. Thereafter, in the photodetector 60, the transmitted light intensity output from the Fabry-Perot interferometer 50 is converted into an electrical signal and output to the arithmetic processing unit 70.

Subsequently, in step S7, the arithmetic processing unit 70 outputs the second transverse wave ultrasonic wave W _S2 , the longitudinal wave ultrasonic wave W _T2 output from the photodetector 60 in step S6, and the surface ultrasonic wave W displaced in the plate thickness direction. _The electrical signal related to each ultrasonic wave of _H2 is stored in the waveform data storage unit 72 as waveform data representing the frequency change of the laser beam L20 in each ultrasonic wave.

Subsequently, in step S8, the first sound velocity calculation unit 731 has a frequency of the laser beam L20 in the first transverse wave ultrasonic wave W _S1 detected by the Fabry-Perot interferometer 50 stored in the waveform data storage unit 72. based on the waveform data showing a change, the first transverse ultrasonic wave W _S1 is determined propagation time having propagated inside of the measurement plate 101, the determined based on the propagation times said first transverse ultrasonic wave W _S1 Is calculated as the first sound speed V _S1 .

Subsequently, in step S9, the second sound speed calculation unit 732 stores the frequency of the laser beam L20 in the second transverse wave ultrasonic wave W _S2 detected by the Fabry-Perot interferometer 50 and stored in the waveform data storage unit 72. based on the waveform data showing a change, the second transverse ultrasonic wave W _S2 is determined propagation time having propagated inside of the measurement plate 101, the second transverse ultrasonic wave W _S2 based on the determined propagation time _Is calculated as the second sound speed V _S2 .

Subsequently, in step S10, the third sound velocity calculation unit 733 calculates the frequency change of the laser beam L20 in the longitudinal wave ultrasonic wave W _T1 detected by the Fabry-Perot interferometer 50, which is stored in the waveform data storage unit 72. Based on the represented waveform data, a propagation time in which the longitudinal wave ultrasonic wave W _T1 propagates through the measurement target plate 101 is obtained, and the sound speed of the longitudinal wave ultrasonic wave W _T1 is calculated based on the obtained propagation time. Calculated as V _T. Note that the third sound speed calculation unit 733 of the present embodiment calculates the sound speed of the longitudinal ultrasonic wave W _T1 as the third sound speed V _T , but the sound speed of the longitudinal wave ultrasonic wave W _T2 as the third sound speed V _T. Alternatively, the sound velocity of the longitudinal ultrasonic wave W _{T1 and} the sound velocity of the longitudinal wave ultrasonic wave W _T2 may be calculated, and predetermined processing such as averaging processing may be performed for each sound velocity. it may be calculated third sound speed V _T to go.

Subsequently, in step S11, the fourth sound speed calculation unit 734 stores the laser beam in the surface ultrasonic wave W _H1 that is stored in the waveform data storage unit 72 and is displaced in the thickness direction detected by the Fabry-Perot interferometer 50. Based on the waveform data representing the frequency change of L20, the propagation time during which the surface ultrasonic wave _WH1 displaced in the plate thickness direction propagates through the surface of the measurement target plate 101 is obtained, and the plate thickness is obtained based on the obtained propagation time. The sound speed of the surface ultrasonic wave W _H1 that is displaced in the direction is calculated as the fourth sound speed V _H. In the fourth sound velocity calculation unit 734 of the present embodiment, the sound velocity of the surface ultrasonic wave W _H1 that is displaced in the plate thickness direction is calculated as the fourth sound velocity V _H , but the surface ultrasonic wave W that is displaced in the plate thickness direction is calculated. it sound velocity of _H2 may be calculated as the fourth acoustic velocity V _H, or both the speed of sound of the surface ultrasonic W _H2 displaced in the speed of sound and the plate thickness direction of the surface ultrasonic W _H1 displaced in the thickness direction And the fourth sound speed V _H may be calculated by performing a predetermined process such as an averaging process for each sound speed.

Subsequently, in step S12, the elastic constant calculation unit 74 calculates the first sound speed V _S1 calculated by the first sound speed calculation unit 731, the second sound speed V _S2 calculated by the second sound speed calculation unit 732, and the third sound speed calculation. Based on the third sound speed V _T calculated by the unit 733 and the fourth sound speed V _H calculated by the fourth sound speed calculation unit 734, the elastic constant of the polycrystal body constituting the measurement target plate 101 is determined by a predetermined calculation formula. Calculate using.

  Below, the specific calculation method of the elastic constant of the polycrystal which comprises the to-be-measured plate 101 using the predetermined calculation formula in step S12 is demonstrated. In the following description, an example in which a rolled steel plate (hereinafter, this rolled steel plate is referred to as a “rolled steel plate”) will be described as the measurement target plate 101.

A rolled steel sheet is composed of a texture that is a polycrystalline body composed of a single crystal (cubic crystal, hereinafter referred to as an iron single crystal) composed of many fine irons and additive elements, and viewed macroscopically. The case can be considered as a continuum having anisotropy. And the rolled steel plate regarded as a continuum is approximately three planes orthogonal to each other (1. rolling plane (xy plane), 2. plane perpendicular to the rolling plane and parallel to the rolling direction (xz plane) 3) It is considered to have physical properties that are plane-symmetric with respect to the plane perpendicular to the rolling surface and perpendicular to the rolling direction (yz plane)). In such a case, it is known that the elastic modulus tensor (elastic constant matrix) T of the rolled steel sheet has nine different elastic constants C _ij and can be expressed by the following mathematical formula 1 (see Non-Patent Document 1).

On the other hand, it is known that the orientation relationship between a rolled steel plate and an iron single crystal (cubic crystal) constituting the rolled steel plate can be expressed by Euler angles (θ, ψ, φ), and constitutes a rolled steel plate that is a polycrystalline body. It turns out that the proportion of many iron single crystals having a certain direction (Euler angle (θ, ψ, φ)) with respect to the rolled steel sheet can be expressed by the crystal orientation distribution function W (ξ, ψ, φ). ing. This crystal orientation distribution function W (ξ, ψ, φ) is known to be expressed by a series expansion by a product of a generalized Legendre function Z _lmn and two exponential functions as shown in the following formula 2. (See Non-Patent Document 1). However, ξ = cos θ.

In Equation 2, W _lmn is a coefficient of series expansion, and it is known that W ₄₀₀ , W ₄₂₀ , and W ₄₄₀ are related to the elastic properties of the polycrystalline body of the rolled steel sheet. As described above, the elastic modulus tensor T of the rolled steel sheet has nine different elastic constants C _ij, which are six independent values, that is, three elastic constants C ⁰ ₁₁ and C ^{0 of} iron single crystal. ⁰ _12, by C ⁰ ₄₄ a coefficient W ₄₀₀ according to the three crystal orientation distribution function, W _420, W _440, has been found to be expressed by equation 3 equation 11 below (see non-Patent Document 1). However, the elastic constant C ⁰ ₁₁ is a known value of 237 (GPa), the elastic constant C ⁰ ₁₂ is 141 (GPa), the elastic constant C ⁰ ₄₄ is 116 (GPa), and C ⁰ = C ⁰ ₁₁ − C ⁰ ₁₂ -2C ⁰ ₄₄ . That is, if these W _lmn are obtained from ultrasonic measurement, the elastic modulus tensor T (C _ij ) of the rolled steel sheet can be derived.

Also, the first sonic velocity V _S1 which is the sound velocity of the first transverse wave ultrasonic wave polarized in the rolling direction (longitudinal direction) of the rolled steel plate, and the sonic velocity of the second transverse wave ultrasonic wave polarized in the width direction of the rolled steel plate. The relationship between the second sonic velocity V _S2 and the third sonic velocity V _T , which is the sonic velocity of the longitudinal ultrasonic wave propagated in the thickness direction of the rolled steel sheet, and the elastic constant represented by the mathematical formula 1 is as follows: It is known that it can be expressed by Equation 14 (see Non-Patent Document 1). However, (rho) is a density of a rolled steel plate and is a known value.

Further, when the ratio between the second sound speed V _S2 and the third sound speed V _T is K ₁ , the following Expression 15 is obtained from Expression 5, Expression 6, Expression 12, and Expression 13.

Similarly, when the ratio between the first sound speed V _S1 and the third sound speed V _T is K ₂ , the following Expression 16 is obtained from Expression 5, Expression 7, Expression 13, and Expression 14.

In Equations 15 and 16, when known values are substituted into the elastic constants C ⁰ , C ⁰ ₁₁ , and C ⁰ ₄₄ related to the iron single crystal, Equations 15 and 16 represent the coefficients W ₄₀₀ and W ₄₂₀ related to the crystal orientation distribution function. It can be solved because And each solution becomes like the following Numerical formula 17 and Numerical formula 18.

That is, in Equations 17 and 18, the three elastic constants C ⁰ , C ⁰ ₁₁ and C ⁰ ₄₄ relating to the iron single crystal are known values as described above, and the values of K ₁ and K ₂ are also The second sound speed V _S2 and the third sound speed V _T , and the first sound speed V _S1 and the third sound speed V _T have already been calculated in steps S8 to S10, respectively, and the series related to the crystal orientation distribution function. Both W ₄₀₀ and W ₄₂₀ values can be calculated based on the measured sound velocity.

On the other hand, the rolled steel sheet can be regarded as a continuum having orthorhombic symmetry, and the surface ultrasonic wave propagating in the direction of the symmetry axis on the surface of the rolled steel sheet, that is, the speed of sound of the surface ultrasonic wave _{WH1 according to} the present embodiment. The fourth sound speed V _H satisfies the following Expression 19.

In the above Equation 19, the polycrystal elastic constants C ₁₁ , C ₃₁ , C ₃₃ , and C ₅₅ are all expressed in the crystal orientation distribution function as shown in Equation 3, Equation 10, Equation 5, and Equation 7, respectively. Since it can be expressed by such series W ₄₀₀ , W ₄₂₀ and W ₄₄₀ , Equation 19 can be expressed as Equation 20 below.

In Equation 20, as described above, the series W ₄₀₀ and W ₄₂₀ related to the crystal orientation distribution function are known values, and in step S11, the sound velocity of the surface ultrasonic wave W _H1 displaced in the plate thickness direction is the first. Since the 4-sonic velocity V _H has already been calculated, the value of the series W ₄₄₀ related to the remaining crystal orientation distribution function can be calculated.

Through the above processing, three series W ₄₀₀ , W ₄₂₀ , and W ₄₄₀ related to the crystal orientation distribution function can be calculated. Therefore, by substituting these values into Equations 3 to 11, Equation 1 shows Nine different elastic constants in the elastic modulus tensor (elastic constant matrix) T of the rolled steel sheet, that is, all the elastic constants related to the polycrystalline body constituting the rolled steel sheet can be calculated.

In the present embodiment, an example is shown in which the sound velocity of the surface ultrasonic wave W _H1 propagated in the longitudinal direction (rolling direction) of the measurement target plate 101 shown in FIG. 2 is applied as the fourth sound velocity V _H. It is also possible to apply the sound velocity of the surface ultrasonic wave _WH2 propagated in the width direction of the measurement target plate 101 shown in FIG.

When the sound velocity of the surface ultrasonic wave W _H2 shown in FIG. 3 is used as the fourth sound velocity V _H , Equation 21 is applied instead of Equation 19.

In Equation 21 described above, the elastic constants C ₂₂ , C ₂₃ , C ₃₃ , and C ₄₄ of the polycrystal are all expressed in the crystal orientation distribution function as shown in Equation 4, Equation 9, Equation 5, and Equation 6, respectively. Since it can be expressed by such series W ₄₀₀ , W _420, and W ₄₄₀ , Formula 21 can also be expressed as Formula 20, like Formula 19.

Similarly, when the sound velocity of the surface ultrasonic wave W _H2 shown in FIG. 3 is used as the fourth sound velocity V _H , three series W ₄₀₀ , W ₄₂₀ , and W ₄₄₀ related to the crystal orientation distribution function can be calculated. By substituting the values of Equations (3) to (11) into nine different elastic constants in the elastic modulus tensor (elastic constant matrix) T of the rolled steel plate shown in Equation 1, that is, the polycrystalline body constituting the rolled steel plate. All elastic constants can be calculated.

Further, as another method of calculating the elastic constant of the polycrystalline body, as calculated using the speed of sound of the surface ultrasonic W _H1 as the fourth acoustic velocity V _H, the acoustic velocity of the surface ultrasonic W _H2 as the fourth acoustic velocity V _H The elastic constants may be calculated by averaging the values calculated using. By processing in this way, a more accurate elastic constant of the polycrystalline body can be calculated.

  When the elastic constant of the polycrystal body is calculated by the elastic constant calculation unit 74 by this step S12, the calculated elastic constant of the polycrystal body is obtained from the elastic constant calculation unit 74 by measuring the Young's modulus of the plate 101 to be measured, , Sent to various measuring devices for yield strength measurement or tensile strength measurement.

  As described above, in the elastic constant measuring apparatus according to the present embodiment, the ultrasonic wave generation unit 31 generates ultrasonic waves inside and on the surface of the measurement target plate 101 (steps S2 and S5), and the ultrasonic wave detection means First ultrasonic wave generated in the measurement plate 101 and polarized in the longitudinal direction, second ultrasonic wave generated in the measurement plate 101 and polarized in the width direction Transverse wave ultrasonic waves, ultrasonic waves generated inside the measurement target plate 101 and propagated in the plate thickness direction, and ultrasonic waves generated on the surface of the measurement target plate 101 and in the plate thickness direction. Displaced surface ultrasonic waves are respectively detected (steps S3 and S6), the first sound velocity calculation unit 731 calculates the sound velocity of the first transverse wave ultrasonic wave as the first sound velocity (step S8), and the second sound velocity calculation unit 732. In the second The sound velocity of the wave ultrasonic wave is calculated as the second sound velocity (step S9), the sound velocity of the longitudinal ultrasonic wave is calculated as the third sound velocity in the third sound velocity calculating unit 733 (step S10), and the sound velocity of the fourth sound velocity calculating unit 734 is calculated. The sound velocity of the surface ultrasonic wave that is displaced in the plate thickness direction is calculated as the fourth sound velocity (step S11). In the elastic constant calculation unit 74, the polycrystalline body constituting the measured plate 101 based on the first to fourth sound velocities. The elastic constant is calculated using a predetermined calculation formula (step S12).

  Further, in the elastic constant measuring apparatus according to the present embodiment, the ultrasonic wave generator 31 irradiates the surface of the measurement target plate 101 with a laser beam, and the above-described first transverse wave ultrasonic wave, second transverse wave ultrasonic wave, Each of the ultrasonic waves of the longitudinal wave and the surface ultrasonic wave displaced in the plate thickness direction is generated (steps S2 and S5).

  Further, in the elastic constant measuring apparatus according to the present embodiment, the ultrasonic detection unit irradiates a laser beam to a predetermined position on the surface of the measurement target plate 101 and acquires a laser beam reflected at the predetermined position. And a Fabry-Perot interferometer 50 for detecting a change in frequency with respect to the irradiated laser beam caused by vibration of each ultrasonic wave based on the laser beam acquired by the laser beam acquiring unit 41. The first to fourth sound velocity calculation units 731 to 734 are based on waveform data representing the frequency change of the laser beam in each ultrasonic wave detected by the Fabry-Perot interferometer 50. Finds the propagation time of propagation through the inside or surface of the measurement target plate 101, and calculates the sound speed of each ultrasonic wave based on the obtained propagation time.

  According to the elastic constant measuring apparatus according to the present embodiment, it is possible to measure the elastic constant of a polycrystal without using a surface SH wave without contact with the measurement target plate 101 and with a large separation distance.

  Each unit of FIGS. 1 to 3 and FIG. 5 constituting the elastic constant measuring apparatus according to the present embodiment and each step of FIG. 6 showing the elastic constant measuring method is stored in a RAM or ROM of a computer. It can be realized by running the program. This program and a computer-readable storage medium storing the program are included in the present invention.

  Specifically, the program is recorded in a storage medium such as a CD-ROM, or provided to a computer via various transmission media. As a storage medium for recording the program, a flexible disk, a hard disk, a magnetic tape, a magneto-optical disk, a nonvolatile memory card, and the like can be used in addition to the CD-ROM. On the other hand, as the transmission medium of the program, a communication medium (wired line such as an optical fiber, etc.) in a computer network (LAN, WAN such as the Internet, wireless communication network, etc.) system for propagating and supplying program information as a carrier wave A wireless line or the like.

  Moreover, not only the function of the elastic constant measuring apparatus according to the present embodiment is realized by executing a program supplied by a computer, but also an OS (Operating System) or other application in which the program is running on the computer. When the function of the elastic constant measuring apparatus according to the present embodiment is realized in cooperation with software, etc., or all or part of the processing of the supplied program is performed by a function expansion board or function expansion unit of the computer. Such a program is also included in the present invention when the function of the elastic constant measuring apparatus according to the present embodiment is realized.

  When the elastic constant measuring device according to the present invention is realized, the elastic constant is sequentially measured in the manufacturing process of a polycrystalline body such as a steel plate, and the measured value is fed back to the manufacturing process to reduce the variation in the characteristics of the polycrystalline body. In addition, there are effects such as helping to stabilize the production, ranking the characteristics of the polycrystalline body according to the measured value, and changing the post-process to help improve the efficiency of the process.

It is a schematic block diagram of the elastic constant measuring device which concerns on embodiment of this invention. It is a schematic block diagram of the head part in an elastic constant measuring device. It is a schematic block diagram of the head part in an elastic constant measuring device. It is a figure which shows an example of the resonance curve in a Fabry-Perot interferometer. It is the block diagram which showed schematic structure of the arithmetic processing unit in an elastic constant measuring device. It is the flowchart which showed an example of the elastic constant measuring method performed with the elastic constant measuring apparatus which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Ultrasonic generation laser 20 Ultrasonic detection laser 30 Head part 31 Ultrasonic generation part 35 Cylindrical lens 41 Laser beam acquisition part 45a, 45b Condensing lens 46 Half mirror 50 Interferometer (frequency change detection means)
60 Photodetector 70 Arithmetic processing device 71 Head drive control unit 72 Waveform data storage unit 73 Sound speed calculation unit 731 First sound speed calculation unit 732 Second sound speed calculation unit 733 Third sound speed calculation unit 734 Fourth sound speed calculation unit 74 Elastic constant calculation Portions 91a to 91c Optical fiber 92 Condensing lens 101 Measurement plate

Claims (8)

Ultrasonic generation means for generating ultrasonic waves inside and on the surface of the measurement target plate;
The ultrasonic wave generated inside the measurement target plate and polarized in the longitudinal direction of the measurement target plate, the first transverse wave ultrasonic wave, the ultrasonic wave generated inside the measurement target plate and the measurement target plate Second transverse wave ultrasonic waves polarized in the width direction of the wave, ultrasonic waves generated inside the measurement target plate and propagated in the thickness direction of the measurement target plate, and the measurement target plate Ultrasonic detection means for detecting ultrasonic waves generated on the surface of the surface ultrasonic waves that are displaced in the plate thickness direction,
First sound speed calculating means for calculating a sound speed of the first transverse wave ultrasonic wave detected by the ultrasonic wave detecting means as a first sound speed;
Second sound speed calculation means for calculating the sound speed of the second transverse wave ultrasonic wave detected by the ultrasonic wave detection means as a second sound speed;
Third sound speed calculating means for calculating a sound speed of the longitudinal ultrasonic wave detected by the ultrasonic wave detecting means as a third sound speed;
Fourth sound speed calculating means for calculating the sound speed of the surface ultrasonic wave displaced in the plate thickness direction detected by the ultrasonic wave detecting means as a fourth sound speed;
Based on the first sound speed, the second sound speed, the third sound speed, and the fourth sound speed, the ultrasonic waves are generated inside the measurement target plate and are displaced in parallel to the surface of the measurement target plate. An elastic constant measuring device comprising: an elastic constant calculating means for calculating an elastic constant of a polycrystal constituting the plate to be measured using a predetermined calculation formula without using surface ultrasonic waves .   The ultrasonic wave generation unit irradiates a surface of the measurement target plate with a laser beam, and is displaced in the first transverse wave ultrasonic wave, the second transverse wave ultrasonic wave, the longitudinal wave ultrasonic wave, and the plate thickness direction. 2. The elastic constant measuring apparatus according to claim 1, wherein surface acoustic waves are generated. The ultrasonic detection means includes
Laser beam acquisition means for irradiating a predetermined position on the surface of the measurement target plate with a laser beam and acquiring the laser beam reflected at the predetermined position;
Frequency change detection means for detecting a change in frequency with respect to the irradiated laser beam caused by vibration of each ultrasonic wave based on the laser beam acquired by the laser beam acquisition means. ,
The first to fourth sound velocity calculating means are configured to detect each ultrasonic wave inside the measurement target plate based on waveform data representing a frequency change of a laser beam in each ultrasonic wave detected by the frequency change detecting means. 3. The elastic constant measuring apparatus according to claim 1, wherein a propagation time propagated through the surface is obtained, and a sound velocity of each ultrasonic wave is calculated based on the obtained propagation time. An ultrasonic generation step for generating ultrasonic waves inside and on the surface of the measurement plate;
The ultrasonic wave generated inside the measurement target plate and polarized in the longitudinal direction of the measurement target plate, the first transverse wave ultrasonic wave, the ultrasonic wave generated inside the measurement target plate and the measurement target plate Second transverse wave ultrasonic waves polarized in the width direction of the wave, ultrasonic waves generated inside the measurement target plate and propagated in the thickness direction of the measurement target plate, and the measurement target plate An ultrasonic detection step of detecting each ultrasonic wave of the surface ultrasonic wave generated on the surface of the surface and displaced in the plate thickness direction;
A first sound velocity calculating step for calculating a sound velocity of the first transverse wave ultrasonic wave detected in the ultrasonic wave detecting step as a first sound velocity;
A second sound speed calculating step for calculating the sound speed of the second transverse wave ultrasonic wave detected in the ultrasonic wave detecting step as a second sound speed;
A third sound speed calculating step for calculating the sound speed of the longitudinal ultrasonic wave detected in the ultrasonic detection step as a third sound speed;
A fourth sound velocity calculating step for calculating the sound velocity of the surface ultrasonic wave displaced in the plate thickness direction detected in the ultrasonic wave detecting step as a fourth sound velocity;
Based on the first sound speed, the second sound speed, the third sound speed, and the fourth sound speed, the ultrasonic waves are generated inside the measurement target plate and are displaced in parallel to the surface of the measurement target plate. An elastic constant measurement method comprising: calculating an elastic constant of a polycrystal constituting the measurement target plate using a predetermined calculation formula without using surface ultrasonic waves .   In the ultrasonic wave generation step, the surface of the measurement target plate is irradiated with a laser beam to be displaced in the first transverse wave ultrasonic wave, the second transverse wave ultrasonic wave, the longitudinal wave ultrasonic wave, and the plate thickness direction. 5. The elastic constant measuring method according to claim 4, wherein surface ultrasonic waves are generated. The ultrasonic detection step includes
A laser beam acquisition step of irradiating a predetermined position on the surface of the measurement target plate with a laser beam and acquiring the laser beam reflected at the predetermined position;
A frequency change detecting step for detecting a change in frequency with respect to the irradiated laser beam caused by the vibration of each ultrasonic wave based on the laser beam acquired in the laser beam acquiring step. ,
In the first to fourth sound velocity calculation steps, each ultrasonic wave is generated inside the measurement target plate based on the waveform data representing the frequency change of the laser beam in each ultrasonic wave detected in the frequency change detection step. 6. The elastic constant measuring method according to claim 4 or 5, wherein a propagation time propagated through the surface is obtained, and a sound velocity of each ultrasonic wave is calculated based on the obtained propagation time. An ultrasonic generation step for generating ultrasonic waves inside and on the surface of the measurement plate;
The ultrasonic wave generated inside the measurement target plate and polarized in the longitudinal direction of the measurement target plate, the first transverse wave ultrasonic wave, the ultrasonic wave generated inside the measurement target plate and the measurement target plate Second transverse wave ultrasonic waves polarized in the width direction of the wave, ultrasonic waves generated inside the measurement target plate and propagated in the thickness direction of the measurement target plate, and the measurement target plate An ultrasonic detection step of detecting each ultrasonic wave of the surface ultrasonic wave generated on the surface of the surface and displaced in the plate thickness direction;
A first sound velocity calculating step for calculating a sound velocity of the first transverse wave ultrasonic wave detected in the ultrasonic wave detecting step as a first sound velocity;
A second sound speed calculating step for calculating the sound speed of the second transverse wave ultrasonic wave detected in the ultrasonic wave detecting step as a second sound speed;
A third sound speed calculating step for calculating the sound speed of the longitudinal ultrasonic wave detected in the ultrasonic detection step as a third sound speed;
A fourth sound velocity calculating step for calculating the sound velocity of the surface ultrasonic wave displaced in the plate thickness direction detected in the ultrasonic wave detecting step as a fourth sound velocity;
Based on the first sound speed, the second sound speed, the third sound speed, and the fourth sound speed, the ultrasonic waves are generated inside the measurement target plate and are displaced in parallel to the surface of the measurement target plate. A program for causing a computer to execute an elastic constant calculation step of calculating an elastic constant of a polycrystal constituting the measurement target plate using a predetermined calculation formula without using surface ultrasonic waves .   A computer-readable storage medium in which the program according to claim 7 is stored in a computer-readable manner.

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