JP7787402B2 - Panel material and method for manufacturing panel material - Google Patents

Description

This disclosure relates to panel materials and methods for manufacturing panel materials.

Low heat-transfer steel has been known as a framing material used in panel materials such as exterior walls and flooring. Low heat-transfer steel can be produced, for example, by drilling one or more holes in the web of a channel steel stud, which acts as a thermal bridge in an exterior wall.

The holes extend the length of the heat transfer path through the web located between the pair of flanges and reduce the cross-sectional area of the transfer path. As a result, the thermal conductivity of the web decreases, improving the insulating performance of low-heat-transfer steel sections that use channel steel with perforated webs. When comparing channel steel sections of the same shape and dimensions, for example, the insulating performance of low-heat-transfer steel sections that use channel steel with perforated webs is better than that of channel steel sections with non-perforated webs.

In this specification, for the sake of convenience, lip channel steel with a perforated web will be referred to as "low heat transfer steel," and lip channel steel with a non-perforated web will be referred to as "normal steel."

As an example of technology related to low heat transfer steel, Patent Document 1 discloses lip channel steel as a frame material used in panel materials such as building wall materials. In the lip channel steel of Patent Document 1, the cross-sectional area of the web when cut at a plane perpendicular to the material axis is reduced by making the cross-sectional area at the center in the web height direction smaller than the cross-sectional area near the flanges at both ends, thereby reducing the thermal conductivity of the web. Patent Document 1 discloses a technique of drilling holes in the plate surface of the web as an example of a method for reducing the cross-sectional area.

Patent Document 2 also discloses low-heat-conductivity steel sections in which the web of a channel steel structural metal plate is cut and raised at the sides, creating slits in the web to reduce thermal conductivity.

Japanese Patent Application Laid-Open No. 2000-87505 Japanese Patent Application Laid-Open No. 2002-146936

Here, in low-heat-conductivity channel steel, the holes drilled in the web act as cross-sectional defects in the web. This improves the insulating performance of the panel material. However, in terms of structural performance, the bending strength of channel steel with perforated webs is lower than that of channel steel with non-perforated webs. It has been found that in low-heat-conductivity lip channel steel, when bending loads due to wind pressure or the like are applied to the flanges through the face material joined to the flanges, distortional buckling, a phenomenon unique to low-heat-conductivity steel, i.e., localized deformation of the web, is likely to occur.

In this regard, Patent Document 1 does not disclose any technology for suppressing buckling, which is specific to low-heat-transfer steel, and improving strength when a bending load is applied to channel steel. Therefore, the technology in Patent Document 1 alone cannot solve the problem of reduced strength caused by buckling, which is specific to low-heat-transfer steel in lip channel steel.

Furthermore, while Patent Document 2 is a technology related to low heat transfer steel sections, the inventors' investigations have revealed that even when side walls are provided, it may not necessarily be possible to fully resolve the problem of reduced strength due to buckling, which is unique to lip channel steel sections made of low heat transfer steel sections. Therefore, there is a need for new technology that can suppress the reduction in strength due to buckling in lip channel steel sections made of low heat transfer steel sections.

In light of the above-mentioned problems, the present disclosure aims to provide a panel material with improved thermal insulation performance due to the use of lip channel steel with perforated webs as low heat transfer steel, which can suppress the reduction in strength due to buckling that is unique to low heat transfer steel, and a method for manufacturing the panel material.

A panel material according to one aspect of the present disclosure comprises a lip channel steel having a web, a pair of flanges, and a pair of lips, with holes in the web that improve the thermal insulation performance of the channel steel; a face material; and a plurality of joining members that join at least one of the flanges to the face material, wherein, when the plate surface of the face material is viewed from the front, the joining members are arranged in a staggered pattern, or in two linear rows arranged parallel to each other with a space between them in the flange width direction, with multiple joining members arranged in a linear pattern along the axial direction of the lip channel steel.

As a result of the inventors' research, it was found that in low-heat-transfer steel sections using lip channel steel, when multiple joining members joining the flange and face plate are arranged in a staggered pattern, the bending strength of the lip channel steel increases compared to when the joining members are arranged in a single row, even if the number of joining members is the same.

In addition, it was found that when multiple connecting members are arranged in two rows in a straight line along the axial direction of the lip channel steel, with a gap between them in the flange width direction, the bending strength of the lip channel steel increases compared to when the connecting members are arranged in a single row.

For this reason, the panel material according to one embodiment of the present disclosure can suppress the reduction in strength due to buckling, which is unique to low heat transfer steel, in lip channel steel made of low heat transfer steel with improved thermal insulation performance.

A method for manufacturing a panel material according to another aspect of the present disclosure joins at least one flange of a lip channel steel, which has a web, a pair of flanges, and a pair of lips and has holes in the web that improve the thermal insulation performance of the channel steel, to a face material layered on at least one of the flanges, with multiple joining members arranged in a staggered pattern when viewing the plate surface of the face material from the front, or with two rows of multiple joining members arranged linearly along the axial direction of the lip channel steel and arranged parallel to each other with a space between them in the flange width direction.

According to another aspect of the present disclosure, the panel material according to the above aspect can be manufactured.

Accordingly, this disclosure provides a panel material and a method for manufacturing the panel material, which has improved thermal insulation performance due to the use of lip channel steel with perforated webs as low heat transfer steel, and which can suppress the reduction in strength due to buckling that is unique to low heat transfer steel.

FIG. 1 is a perspective view illustrating a panel material including a frame material according to an embodiment of the present disclosure. FIG. 2(A) is a plan view of a panel material according to this embodiment in which joining members are arranged in two parallel rows, and FIG. 2(B) is a cross-sectional view taken along line 2B-2B in FIG. 2(A). FIG. 3A is a plan view of a panel material according to another embodiment in which the joining members are arranged in a staggered pattern, and FIG. 3B is a cross-sectional view taken along line 3B-3B in FIG. 3A. FIG. 4(A) is a front view of the outer surface of the web of the lip channel steel of the frame member according to this embodiment, and FIG. 4(B) is a side view of the lip channel steel. FIG. 10 is a front view of the outer surface of the web when the slit joints are arranged in series. 10 is a graph illustrating the relationship between the slit ratio and the heat transmission reduction rate when the slit arrangement pattern is changed. FIG. 2 is a diagram illustrating an outline of an analytical model of a lip channel steel of a low heat transfer steel according to Example 1. FIG. 8A is a plan view of a panel material according to a comparative example in which the joining members are arranged in a single row, and FIG. 8B is a cross-sectional view taken along line 8B-8B in FIG. 8A. Figure 9(A) is a diagram illustrating the cross-sectional deformation at the center of the material axis direction of the analysis model according to Example 1, and Figure 9(B) is a diagram illustrating the cross-sectional deformation at the center of the material axis direction of the analysis model according to the comparative example. 10A and 10B are diagrams illustrating the relationship between displacement and load at the center of each of the analytical models of the example and the comparative example. FIG. 11(A) is a diagram illustrating the positions of the joining members in an analysis model when the joining members are arranged in two parallel rows, and FIG. 11(B) is a diagram illustrating the positions of the joining members in an analysis model when the joining members are arranged in a staggered manner. Figure 12(A) is a diagram illustrating an overview of an analytical model of a lip channel steel made of low heat transfer steel in an embodiment, and Figure 12(B) is a diagram illustrating an overview of an analytical model serving as a reference model of a lip channel steel made of low heat transfer steel. 10 is a graph illustrating the relationship between the joining interval of the joining members and the maximum bending strength. 10 is a graph illustrating the relationship between the row spacing of joining members and the maximum bending strength. 10 is a graph illustrating the relationship between the joint spacing of joint members arranged in two parallel rows and the maximum bending strength, with different plate thicknesses. 10 is a graph illustrating the relationship between the joint spacing of staggered joint members and the maximum bending strength when the plate thickness is changed. 10 is a graph illustrating the relationship between the joint spacing of the joint members and the maximum bending strength when the lip length of the panel material is changed. 10A and 10B are diagrams illustrating positions of joint members in an analytical model of joint members having an arrangement pattern in which auxiliary positions are added to a two-row parallel arrangement. 10 is a graph illustrating the relationship between the joining interval of the joining members and the maximum bending strength, separately for the cases where the joining members are arranged at the auxiliary positions and where they are not arranged.

Embodiments of the present disclosure are described below. In the following drawings, identical or similar parts are designated by the same or similar reference numerals. However, the relationship between thickness and planar dimensions in the drawings, and the thickness ratios of each device and component, may differ from the actual ones. Therefore, specific thicknesses and dimensions should be determined with reference to the following description. Furthermore, there are parts in which the dimensional relationships and ratios differ between the drawings.

<Panel material>
First, a panel material 10 according to this embodiment will be described with reference to Figures 1 to 6. As shown in Figure 1, the panel material 10 according to this embodiment includes a lip channel steel 12, a face material 14 joined to the upper flange 12B, and a face material 22 joined to the lower flange 12B. A filler member 24 is disposed between the upper face material 14 and the lower face material 22. Note that in Figure 1, portions of the face materials 14 and 22 are illustratively cut away to make the lip channel steel 12 easier to see.

(Lip channel steel)
The lip channel steel 12 has a web 12A, a pair of flanges 12B, and a pair of lips 12C. The lip channel steel 12 can be made from a single steel plate by, for example, bending. In the present disclosure, the steel plate has a thickness of 2.3 mm or less.

In this embodiment, the lip channel steel 12 may be formed using a high-strength steel plate of 500 MPa or more. In this specification, "high-strength steel plate" refers to a steel plate (steel material) having an F-value, as a strength, of 500 MPa or more and 1000 MPa or less. In addition, in contrast to "high-strength steel plate," a steel plate having an F-value of less than 500 MPa may be referred to as "normal steel plate." In this embodiment, for example, a steel material having an F-value of 280 MPa for 400 material as a normal steel plate may be used, or a steel material having an F-value of 500 MPa as a high-strength steel plate may be used.

If the F-value, which indicates the strength of the steel plate, exceeds 1000 MPa, the strength becomes too high, resulting in reduced workability when forming the steel plate into lip channel steel 12, for example, by roll forming. For this reason, in this embodiment, the strength of the high-strength steel plate is specified to be 1000 MPa or less. However, in this disclosure, the strength of the high-strength steel plate is not limited to this and can be changed as appropriate.

(lip)
In this embodiment, the lip lengths L of the pair of lips 12C are equal to each other, but in the present disclosure, the lip lengths of the pair of lips may be different from each other. The "lip length L" is the maximum length of the lip 12C measured in a cross section perpendicular to the material axis direction D of the lip channel steel 12, as shown in Figure 4(B) . In addition, the flange widths of the pair of flanges 12B located above and below in Figure 4(B) may also be different from each other.

Here, in this embodiment, it is assumed that the flange 12B, which is joined to the face material 14, is subjected to an external compressive force, i.e., bending, in the out-of-plane direction of the face material 14.

(Surface material)
As shown in FIG. 2A , the face material 14 is a rectangular building component when viewed from the front. The face material 14 is, for example, a plate-shaped base material or gypsum board. In this embodiment, the face material 14 is an exterior wall material, but the present disclosure is not limited thereto and may be, for example, another panel material such as a flooring material. Furthermore, while the present embodiment illustrates a case in which the face material is joined to both of the pair of flanges 12B, the present disclosure is not limited thereto and may instead be joined to only the upper flange 12B or only the lower flange 12B in FIG. 1 .

Furthermore, the upper face material 14 and the lower face material 22 in Figure 1 may be members having similar functions, or may be members having different functions. The face material 14 simply needs to be joined by the joining member 20 to the plate surface of the flange 12B on at least one side where a compressive force is generated.

(Filling member)
In the present embodiment, the filler member 24 is a heat insulating material such as glass wool or cellulose fiber, but the present disclosure is not limited to this and can be changed as appropriate. Also, the filler member is not essential in the present disclosure.

(Joining member)
The joining members 20 are, for example, screws or the like, and are architectural components that join the flange 12B and the face material 14. Fig. 2(A) illustrates, when viewed from the front of the plate surface of the face material 14, two rows of multiple joining members 20 arranged linearly along the material axis direction of the lip channel steel 12 (the Z direction extending vertically in Fig. 2(A)), arranged in parallel with a space in the flange width direction. Note that in the present disclosure, the number of rows can be set to any number greater than two.

In the following explanation, for the sake of convenience, the state in which two rows arranged linearly along the material axis direction D are arranged parallel to each other with a gap in the flange width direction will be referred to simply as a "two-row parallel arrangement." The arrangement pattern of the joining members will be explained in detail later.

(web)
As shown in FIG. 4(A), in this embodiment, the web 12A is provided with a row of slits 16 arranged linearly at approximately equal intervals G along the material axis direction D. The slits 16 are holes that improve the thermal insulation performance of the channel steel. Three rows of slits 16 are formed at approximately equal intervals G along the vertical direction in FIG. 4(A). The "material axis direction D" is the direction in which the web 12A and flange 12B of the lip channel steel 12 extend along the left-right direction in FIG. 4(A). In other words, the material axis direction D is equal to the longitudinal direction.

As shown in Figure 4(B), "web height HW" is the linear distance in the vertical direction from the end of one flange 12B to the end of the other flange 12B. Furthermore, "flange width WF" is the linear distance in the horizontal direction from the end of the web 12A to the end of the lip 12C in Figure 4(B). Furthermore, "lip length L" is the linear distance in the vertical direction from the end of one flange 12B of the lip 12C to the end of the other lip 12C in Figure 4(B). For example, the lip length L of the upper lip 12C in Figure 4(B) is the linear distance between the upper surface of the upper end, which is located at the same height as the upper surface of the upper flange 12B, and the lower surface of the lower end of this upper lip 12C.

Furthermore, in the present disclosure, the number of rows containing slits 16 is not limited to three rows, but may be one row, or any number of rows of two or more, such as five rows. From the perspective of improving thermal insulation performance, it is desirable to form three or more rows of slits 16.

In addition, in the present disclosure, the spacing G in the material axis direction D between adjacent slits 16 in one row is not limited to being equal, but may be different. Furthermore, the spacing G between adjacent rows in the web height direction is also not limited to being equal, but may be different. Furthermore, in order to avoid stress concentration, it is preferable that the shape of the longitudinal end of the slit 16 be arc-shaped, as shown in Figure 1.

(joint part)
In this embodiment, a connecting portion 18 is formed in the web 12A at a portion where a gap G in the material axis direction D is formed between adjacent linear slits 16 having a constant length M in a row of the web 12A, connecting the plate members of the web 12A in the height direction.

In the present disclosure, the shape and dimensions of the holes drilled in the web 12A are not limited to slits and can be changed as appropriate. Furthermore, in the present disclosure, the number of slits included in one row can be any number as long as it is two or more. In the present disclosure, it is sufficient that at least one connecting portion is formed, as long as the necessary strength as a component is ensured.

In this embodiment, in a plan view of the front surface of the web 12A, the arrangement pattern of the multiple connecting portions 18 included in the three rows of slits 16 is staggered. Specifically, the slits 16 included in each of the three rows are offset so as not to overlap on a straight line along the web height direction.

In other words, if the slits 16 are staggered, when the plate surface of the web 12A is viewed from the front, the path along which heat moves from one flange 12B side to the other flange 12B side is prevented from being the shortest distance equal to the web height HW. Furthermore, when the slits 16 are staggered, it is possible that the connecting portions 18 will also be staggered.

In addition, in this disclosure, "a state in which the slits are staggered" is not limited to a state in which the slits are staggered in all rows of slits 16 formed in the web 12A. In this disclosure, "a state in which the slits are staggered" can also include a state in which the slits are staggered partially in at least one of the material axis direction D and the web height direction.

Note that in the present disclosure, the arrangement pattern of the multiple slits is not limited to a staggered arrangement. As shown in Figure 5, the slits 16 may also be arranged in series so that they overlap on a straight line along the web height direction (the up-down direction in Figure 5).

(Slit ratio)
In the present disclosure, the slit ratio is defined as the sum of the spacings G between adjacent slits 16 in the material axis direction D of the web 12A divided by the sum of the lengths M of the slits 16. Note that in the present disclosure, the "slit spacing" includes both a spacing formed between two slits and a spacing formed between one slit and the other end of the web in the material axis direction.

(Analysis test of heat transmission coefficient reduction rate)
6 illustrates the heat transmission coefficient reduction rate calculated from the results of analyzing the heat transmission coefficient of panel materials using low heat conduction steel of lip channel steel 12 with different slit ratios using finite element numerical analysis (FEM). Specifically, the heat transmission coefficient reduction rate of an analytical model of lip channel steel 12 in which the joints 18 are arranged in a series pattern and the heat transmission coefficient reduction rate of an analytical model of lip channel steel 12 in which the joints 18 are arranged in a staggered pattern are illustrated.

The lip channel steel 12 used in the two analysis models in Figure 6 have the same shape and dimensions, except for the arrangement pattern of the joints 18. Also, in Figure 6, data points for when the arrangement pattern of the joints 18 is a staggered arrangement are illustrated by five black circles, and data points for when the arrangement pattern of the joints 18 is a serial arrangement are illustrated by seven white circles.

In the analysis test, five exterior wall components with different slit ratios were created as analysis models. Each component was made of low-heat-conductivity steel lip channel steel 12 (a stud material), with one structural face plate 14, insulation as a filler member 24, and gypsum board as a face plate 22 attached to the other. Specifically, in the shape of the lip channel steel 12 with three rows of slits 16 shown in Figure 4(A), the length M and spacing G of the slits 16 were changed to create different slit ratios. The five joints 18 were all arranged in a staggered pattern. An analysis was then performed using the created analysis models to analyze the respective thermal transmittances.

In addition, a lip channel steel with a non-perforated web and the same shape and dimensions as the analytical model was set as a reference model for comparison. An analysis was then performed on the set reference model to analyze the thermal conductivity of the reference model.

The "Decrease in Heat Transmission Coefficient" on the vertical axis of the graph in Figure 6 is the value obtained by dividing the heat transmission coefficient of the analytical model with slits 16 by the heat transmission coefficient of the reference model. A larger decrease in heat transmission coefficient, i.e., the closer the decrease in heat transmission coefficient is to 1, means that the degree of decrease is small and therefore the thermal insulation performance is not improved. On the other hand, a smaller decrease in heat transmission coefficient means that the degree of decrease is large and therefore the thermal insulation performance is improved.

As can be seen from the data points marked with black circles in Figure 6, when the joints 18 are arranged in a staggered pattern, the reduction in heat transmission coefficient is 85% or less when the slit ratio is 20% or less. In other words, the thermal insulation performance can be improved by 15% or more. On the other hand, when the slit ratio exceeds 20%, the improvement in thermal insulation performance is less than 15%.

Furthermore, from the perspective of thermal insulation performance, a smaller slit ratio is preferable, but if the slit ratio is too small, the strength of the lip channel steel 12 as a structural member, i.e., its structural performance, becomes unstable. For this reason, in this embodiment, the slit ratio is set in the range of 5% or more and 20% or less, which is a range that achieves a good balance between structural performance and thermal insulation performance. Note that in the present disclosure, the slit ratio range is not limited to this and can be changed as appropriate depending on the desired specifications of the lip channel steel 12.

Furthermore, as can be seen from the data points marked with white circles in Figure 6, even when the joints 18 are arranged in series, thermal insulation performance can be effectively improved if the slit ratio is set within the range of 5% or more and 20% or less. However, even with the same slit ratio, the analytical model of lip channel steel 12 with staggered joints 18 has a smaller rate of decrease in thermal transmittance than the analytical model of lip channel steel 12 with serial joints 18, resulting in a greater improvement in thermal insulation performance.

(Arrangement pattern of joining members)
Next, the arrangement pattern of the joining members 20 according to this embodiment will be specifically described. Fig. 2(B) illustrates a center line C that extends vertically through the center of the flange in the width direction. As shown in Fig. 2(B), in this embodiment, the joining members 20 arranged in parallel in two rows sandwich the center of the flange in the width direction, but are not arranged in the center. Note that in the present disclosure, the joining members 20 may also be arranged at the center of the flange in the width direction.

Here, a two-row parallel arrangement refers to an arrangement pattern in which joining members 20 arranged continuously in one row along the material axis direction D overlap with joining members 20 arranged continuously in the flange width direction along the material axis direction D in an adjacent row in the flange width direction.

Furthermore, in the present disclosure, the arrangement pattern of the multiple joining members 20 is not limited to two parallel rows. For example, as shown in FIG. 3(A), when the plate surface of the face material 14 is viewed from the front, the multiple joining members 20 may be arranged in a staggered pattern. In FIG. 3(B), an example is shown in which the staggered joining members 20 are arranged on either side of the center of the flange width direction, but are not arranged in the center. Note that in the present disclosure, the staggered joining members may also be arranged in the center of the flange width direction.

The staggered arrangement of the joining members 20 is defined in the same way as the staggered arrangement of the joints 18 between the slits 16 described above. In other words, joining members 20 arranged continuously in one row along the material axis direction D are offset from joining members 20 arranged continuously in the material axis direction D in an adjacent row in the flange width direction so as not to overlap on a straight line along the flange width direction.

In other words, the staggered arrangement can also be configured in two rows each formed by connecting members 20 arranged continuously along the material axis direction D. On the other hand, the staggered arrangement can also be configured, for example, by a first row formed by two connecting members 20 arranged continuously along the material axis direction D, and a single connecting member 20 that does not form a row. The single connecting member 20 is spaced apart from the first row in the flange width direction and is offset so as not to overlap either of the two connecting members 20 in the first row in the flange width direction.

In addition, in this disclosure, "a state in which the joining members 20 are staggered" does not necessarily mean that the joints are staggered in all rows of the joining members 20. In this disclosure, a state in which the joining members 20 are staggered in only a portion of all rows of the joining members 20 can also be included in "a state in which the joining members 20 are staggered." For this reason, in this disclosure, two rows formed by a plurality of joining members 20 may, for example, include a mixture of a partially staggered state and a partially parallel two-row arrangement.

(Manufacturing method of panel material)
A method for manufacturing a panel material having an arrangement pattern of joining members 20 according to this embodiment can be achieved by joining the flange of a lip channel steel and a face material 14 placed on the flange with a plurality of joining members 20 arranged in a staggered pattern when viewing the plate surface of the face material 14 from the front. Alternatively, a panel material having an arrangement pattern of joining members 20 according to this embodiment can be manufactured by joining two rows of joining members 20 arranged linearly along the material axis direction of the lip channel steel in parallel with a gap in the flange width direction.

Next, examples of the lip channel steel 12 of the panel material 10 according to this embodiment will be described with reference to Figures 7 to 19.

Example 1: Relationship between load and displacement
In Example 1, an analysis was performed using FEM to generate a forced displacement in order to simulate a compressive force applied along the out-of-plane direction of the lip channel steel 12 .

Specifically, an analytical model was set up as shown in Figure 7. The length of the analytical model in the material axis direction D was 3900 mm, the web height HW was 100 mm, the flange width WF was 50 mm, the lip length L was 20 mm, and the plate thickness t was 1.6 mm. In Example 1, the arrangement pattern of the joining members 20 was a two-row parallel arrangement.

In the analysis, it was assumed that the face plate 14 was joined to the upper flange side of the lip channel steel of the analytical model in Figure 7. Furthermore, the lip channel steel was divided into four equal parts in the material axis direction D, and a four-point bending test was performed in which a forced vertical displacement from top to bottom in Figure 7 was set at two points on both ends, applying force to the central part sandwiched between the two central points. Furthermore, displacement of the central part in the flange width direction was restrained to prevent lateral buckling. Furthermore, as a boundary condition, one end of the lip channel steel in the material axis direction D was set to be pin-supported, and the other end was set to be roller-supported.

A load was then applied to each of the set analysis models, and the deformation state of the center in the material axis direction D was analyzed. Furthermore, the bending strength of each model was analyzed from the analysis results. Below, the analysis results of a lip channel steel 12 in which the connecting members 20 are arranged in two parallel rows will be described as Example 1. In the analysis, rotation and displacement in the flange width direction of the center were constrained to represent the state of Example 1. Furthermore, as shown in Figure 8 (A), the analysis results of a lip channel steel 12 of a panel material 10Z in which the connecting members 20 are arranged in a single row will be described as Comparative Example 1.

In the analysis, to represent the state of the first comparative example, rotation in the width direction of the central flange was not constrained, and only displacement was constrained. As shown in Figure 8 (B), in the first comparative example, the connecting members 20 arranged in a single row overlap with the center line C, which extends vertically through the center of the flange in the width direction. The analysis conditions for the frame material in the panel material 10Z of the first comparative example are the same as those in Example 1, except for the arrangement pattern of the connecting members 20.

As a second comparative example, an analytical model of a regular lip channel steel section with a web without holes was created, and an analysis similar to that of Example 1 and the first comparative example was performed. For the second comparative example, two types of analytical models were prepared: one in which the joining members 20 were arranged in a single row, and one in which the joining members 20 were arranged in a two-row parallel row. The conditions other than the holes for the analytical model of the second comparative example with a single row arrangement pattern were the same as those for the first comparative example. The conditions other than the holes for the analytical model of the second comparative example with a two-row parallel arrangement pattern were the same as those for Example 1.

In Figures 9(A) and 9(B), the dashed lines illustrate the cross-sectional shape of the center of each lip channel steel in the material axis direction D before a compressive force is applied from above. Also, in Figures 9(A) and 9(B), the solid lines illustrate the state of the cross-sectional shape of the center, which has bent downward and deformed at maximum strength after a compressive force is applied from above. Figure 9(A) illustrates the cross-sectional shape of the analysis model for Example 1, and Figure 9(B) illustrates the cross-sectional shape of the analysis model for Comparative Example 1.

As shown in Figures 9(A) and 9(B), buckling deformation in Example 1 was suppressed more than in the case of the first comparative example. Although not shown, in both of the two analytical models for the second comparative example, although the central portion in the material axis direction D was bent downward, the overall cross-sectional shape was not significantly deformed, and as a result, buckling deformation was almost nonexistent.

Figure 10 also illustrates trajectories showing the relationship between the vertical displacement δy of the central portion and the load P for each of two analytical models: Example 1, Comparative Example 1, and Comparative Example 2. In Figure 10, the trajectory for Example 1 is shown by a solid line, the trajectory for Comparative Example 1 by a dashed-dotted line, the trajectory for Comparative Example 2 with a single-row arrangement by a dashed line, and the trajectory for Comparative Example 2 with a two-row parallel arrangement by a dotted line.

As shown in Figure 10, in the first comparative example, buckling, which is unique to low heat transfer steel, occurred, leading to a decrease in strength. The maximum strength of the first comparative example is lower than that of the second comparative example. On the other hand, it was found that Example 1, which uses low heat transfer steel and is arranged in two parallel rows, can exhibit strength equivalent to that of the two types of second comparative example, which uses normal steel. It was found that Example 1 can suppress the occurrence of buckling, which is unique to low heat transfer steel, and prevent a decrease in strength due to cross-sectional loss in the web.

In addition, although not shown in the figures, an analytical model was set up with a staggered arrangement as a different arrangement pattern for the connecting members 20 of Example 1. In the staggered arrangement analytical model, the number of connecting members 20 is the same as the number of connecting members used in the first comparative example with a single row arrangement. The analysis conditions other than the arrangement pattern of the connecting members 20 and the number of connecting members 20 are the same as the analysis conditions for the two-row parallel arrangement. As a result, it was found that Example 1 with a staggered arrangement can exhibit a strength equivalent to that of the two types of second comparative example, which are ordinary steel sections.

Example 2: Relationship between joint spacing and rate of increase in maximum bending strength (two-row parallel arrangement)
Next, in Example 2, the maximum bending strength of the lip channel steel 12 when the joining interval in the material axis direction D of the joining member 20 is changed is analyzed using FEM.

The analysis model for Example 2 was set as a four-point bending model, as in Example 1. In Example 2, two types of analysis were set: one where the joining members 20 are arranged in two parallel rows as shown in Figure 11(A), and one where the joining members 20 are arranged in a staggered pattern as shown in Figure 11(B).

As shown in Figure 12(A), the cross-sectional shape of the analytical model for Example 2 was set to a web height HW of 100 mm, a flange width WF of 50 mm, a lip length L of 12 mm, and a plate thickness t of 1.6 mm. The shape of the cross-sectional defect in the web 12A, i.e., the shape of the slit, was the same as in Example 1. Furthermore, the displacement δx from the center of the flange width direction at each position in the flange width direction of the two rows of connecting members 20 was set to 10 mm. In other words, the row spacing in the flange width direction for the two rows of connecting members 20 was 20 mm.

On the other hand, as shown in Figure 12 (B), a reference model was set up to compare the maximum bending strength. The cross-sectional shape of the reference model was the same as in Example 2. However, the arrangement pattern of the connecting members 20 in the reference model was a single row, and the connecting members 20 were arranged along the center line C in the flange width direction.

Although not shown in the figures, an analytical model of a lip channel steel of a normal steel section in which the connecting members 20 are arranged in two parallel rows was set as the third comparative example. The analytical conditions for the third comparative example are the same as those for Example 2 in which the connecting members 20 are arranged in two parallel rows, except for the condition of not having a slit and the constraint condition at the center of the flange width direction.

Then, for each of the two types of low heat transfer steel, Example 2 and the reference model, the buckling strength was measured by changing the joint spacing Dx along the material axis direction D of the joint members 20. The ratio of the maximum bending strength of Example 2 to the maximum bending strength of the reference model was calculated as the rate of increase in maximum bending strength. Similarly, for the third comparative example of ordinary steel, a reference model was set in which the joint members 20 were arranged in a single row, and the rate of increase in maximum bending strength was calculated using the set reference model of ordinary steel.

As shown in Figure 13, in Example 2, which is a two-row parallel arrangement depicted by a solid line, a maximum bending strength increase rate of 1.10 or more was achieved when the spacing between the connecting members 20 was approximately 530 mm or less. In other words, a maximum bending strength increase rate greater than the maximum value of the maximum bending strength increase rate of the third comparative example of ordinary steel, depicted by a dashed line, was achieved. Furthermore, in Example 2, which is a staggered arrangement depicted by a dot-dash line, a maximum bending strength increase rate of 1.10 or more was achieved when the spacing between the connecting members 20 was approximately 200 mm or less. In other words, when the connecting members 20 are arranged in a staggered manner, the strength increased even though the number of connecting members 20 is the same as when the connecting members 20 are arranged in a single row.

Example 3: Relationship between row spacing and rate of increase in maximum bending strength (two-row parallel arrangement)
In Example 3, an analysis was performed using the row spacing in the flange width direction as a parameter when the joining members 20 were arranged in two parallel rows. The cross-sectional shape of the analysis model in Example 3 was the same as in Example 2. The joining spacing Dx in the material axis direction D in Example 3 was set to 150 mm. Note that the joining spacing Dx in the material axis direction D in Example 3 is defined in the same way as the joining spacing Dx exemplified in FIG. 11 .

In Example 3, the row spacing was changed by changing the flange width direction displacement δx of the connecting members 20. The flange width direction displacement δx in Example 3 is defined in the same way as the displacement δx illustrated in Figure 11. Also, in Example 3, as in Example 2, a reference model was set in which the connecting members 20 were arranged in a single row along the material axis direction D, and the maximum bending strength increase rate was calculated using the set reference model.

As shown in Figure 14, when the row spacing was 30 mm, the peak value of the maximum bending strength increase rate was approximately 1.28. However, even when the row spacing was other than 30 mm, a maximum bending strength increase rate of approximately 1.24 or more could be ensured. Therefore, when arranging two rows in parallel, it was found that the row spacing should be 20 mm or more, preferably 40 mm.

Although not shown in the figures, a similar analysis was also performed for cases where the joining members 20 are arranged in a staggered pattern, and the results showed that a row spacing of 20 mm or more, preferably 40 mm, is preferable. However, in this disclosure, the row spacing is not limited to this, and it is sufficient that it is at least equal to or greater than the minimum value required for joining from a design perspective.

<Example 4: Relationship between plate thickness and maximum bending strength increase rate (two-row parallel arrangement)>
In Example 4, in order to confirm the influence of the plate thickness t, FEA was performed using the plate thickness t as a parameter. Specifically, an analytical model similar to that in Example 2, in which the joining members 20 are arranged in two parallel rows, was set up, and three plate thicknesses t of 1.2 mm, 1.6 mm, and 2.3 mm were prepared. Then, using the same reference model as in Example 2, the increase rate of the maximum bending strength for each was calculated.

As shown in Figure 15, in the two-row parallel arrangement, the maximum bending strength tends to increase as the joint spacing decreases, regardless of the three plate thicknesses t. However, even if the joint spacing is reduced, the rate of increase in maximum bending strength when the plate thickness t is 2.3 mm, depicted by the dashed line, is lower than when the plate thickness t is 1.6 mm, depicted by the solid line, and when it is 1.2 mm, depicted by the dashed line, at the same joint spacing.

When the plate thickness t is 2.3 mm, the rate of increase in maximum bending strength is lower than when the plate thickness t is other than 2.3 mm. This is because the larger the plate thickness t, the less likely local deformation of the web 12A occurs than when the plate thickness t is smaller. In other words, according to Example 4, even when the plate thickness t is relatively small, such as 1.2 mm and 1.6 mm, it is possible to effectively increase the bending strength of the lip channel steel 12 by adjusting the joining spacing of the joining members 20.

Furthermore, as shown in Figure 15, when the plate thickness t was 1.6 mm and the joint spacing was 650 mm or less, a maximum bending strength increase rate of 1.10 or more could be achieved. Furthermore, when the plate thickness t was 1.2 mm and the joint spacing was 490 mm or less, a maximum bending strength increase rate of 1.10 or more could be achieved. In other words, in Example 4, it was found that when the plate thickness t was 1.6 mm or less and the joint spacing was 490 mm or less, a maximum bending strength increase rate of 1.10 or more could be achieved.

Example 5: Relationship between joint spacing and rate of increase in maximum bending strength (staggered arrangement)
In Example 5, an analysis of the relationship between the joint spacing and the rate of increase in maximum bending strength when the arrangement pattern of the joint members 20 is a staggered arrangement was performed by changing the plate thickness t. Specifically, an analytical model similar to that in Example 2 in which the joint members 20 are arranged in a staggered arrangement was set up, and three types of plate thicknesses t were prepared: 1.2 mm, 1.6 mm, and 2.3 mm. Then, using the same reference model as in Example 2, the rate of increase in maximum bending strength for each was calculated.

As shown in Figure 16, with the staggered arrangement, similar to the two-row parallel arrangement in Example 4, it can be seen that the maximum bending strength tends to increase for all three plate thicknesses t. Furthermore, when the plate thickness t is 2.3 mm, the rate of increase in maximum bending strength is lower than for the other plate thicknesses t, which is also the same as in Example 4.

Furthermore, as shown in Figure 16, when the plate thickness t was 1.6 mm and the joint spacing was 250 mm or less, a maximum bending strength increase rate of 1.10 or more could be achieved. Furthermore, when the plate thickness t was 1.2 mm and the joint spacing was 200 mm or less, a maximum bending strength increase rate of 1.10 or more could be achieved. In other words, in Example 5, it was found that when the plate thickness t was 1.6 mm or less and the joint spacing was 200 mm or less, a maximum bending strength increase rate of 1.10 or more could be achieved.

Example 6: Relationship between lip length and maximum bending strength increase rate (two-row parallel arrangement and staggered arrangement)
In Example 6, the lip length L of the lip channel steel 12 was divided into cases where it was the required lip length and where it was the effective lip length, and the respective rates of increase in maximum bending strength were compared. Specifically, similar to Example 2, two types of analysis models were set up: one where the connecting members 20 were arranged in two parallel rows and one where they were arranged in a staggered pattern. Then, for each type, an analysis model where the lip length L was the required lip length and an analysis model where it was the effective lip length were prepared. Then, using the same reference model as in Example 2, the respective rates of increase in maximum bending strength were calculated.

(required lip length)
Here, the required lip length is defined by the following calculation formula based on the description on page 83 of "Guidelines for the Design of Thin-Plate Lightweight Steel Buildings, Second Edition" (Japan Iron and Steel Federation).


C _min : Required lip length [mm]
b: Width of flange plate element of lip channel steel etc. [mm]
F: F value of lip channel steel [N/mm ² ]
t: thickness of lip channel steel [mm]

(effective lip length)
The effective lip length is the same as the "effective lip width" described in Table 3.4.4 on page 56 of the "Guidelines for the Design of Lightweight Steel Buildings, Second Edition" (Japan Iron and Steel Federation). Specifically, it is defined by the following formula:

Effective lip length [mm] = (240/√F) × t

The plate thickness t is set in accordance with the design plate thickness described in "(1) Steel Plate Thickness" in the "Guidelines for the Design of Lightweight Steel Buildings, Second Edition," section on page 52, regarding the structural calculation of effective sections. In other words, as a general rule, a plate thickness of 90% of the nominal plate thickness is used.

The arrangement of the effective cross section of the bending member is set in accordance with the arrangement shown in Figure 5.4.5 on page 55 of the "Guidelines for the Design of Lightweight Steel Buildings, Second Edition," and in "(6) Effective Section Modulus Ze of Bending Members" on page 56. In other words, when calculating the allowable stress of bending members, the arrangement of the effective cross section of the bending member differs depending on whether the compression side flange of a lip channel steel subjected to strong axis bending is evaluated with an ineffective portion equivalent to the compression side, or whether the entire plate element is considered effective.

Figure 17 illustrates the results of an analysis model when the connecting members 20 are arranged in two parallel rows. As shown in Figure 17, with a two-row parallel arrangement, the maximum bending strength tends to increase as the joint spacing decreases, regardless of whether the lip length L is the required lip length or the effective lip length. However, the rate of increase in maximum bending strength for the effective lip length depicted by the dashed line is lower than for the required lip length depicted by the solid line, at the same joint spacing, even when the joint spacing is reduced.

When the lip length L is the effective lip length, the rate of increase in maximum bending strength is lower than when it is the required lip length. This is because the cross-sectional area of the lip channel steel increases as the lip length L is extended, making it less likely for local deformation of the web 12A to occur. In other words, according to Example 6, if the lip length L is not as long as the effective lip length but is equal to or greater than the required lip length, it is possible to effectively increase the bending strength of the lip channel steel 12 by adjusting the joining spacing of the joining members 20.

Furthermore, when the connecting members 20 are arranged in two parallel rows, as shown in Figure 17, if the lip length L is equal to or greater than the required lip length and the joining spacing of the connecting members 20 is approximately 650 mm or less, a maximum bending strength increase rate of 1.10 or more can be achieved.

Furthermore, although not shown in the figures, even when the joining members 20 are arranged in a staggered pattern, as in the case of a two-row parallel arrangement, a maximum bending strength increase rate of 1.10 or more can be achieved, as long as the lip length L is equal to or greater than the required lip length.

<Modification: Joining members arranged at auxiliary positions (arranged in two parallel rows)>
As shown in Figure 18, in a lip channel steel for a panel material according to a modified example of this embodiment, a plurality of joining members 20 may be arranged along the material axis direction D at auxiliary positions set between two rows of joining members 20 arranged in parallel. The auxiliary positions halve the row spacing in the flange width direction (vertical direction in Figure 18) and also halve the joint spacing Dx in the material axis direction D (horizontal direction in Figure 18).

In the present disclosure, the number of auxiliary positions that are set may be one, or any number greater than or equal to two. Furthermore, auxiliary positions may be set between three or more rows of joining members 20 that are arranged in parallel.

Example 7: Relationship between connecting members at auxiliary positions and rate of increase in maximum bending strength
In Example 7, an analysis was performed on the rate of increase in maximum bending strength of lip channel steel according to the modified example illustrated in Fig. 18. Specifically, in the analysis model of Example 7, an auxiliary position was additionally set at the center position in the flange width direction of the flange 12B between the two rows of connecting members 20 arranged in parallel in an analysis model similar to the analysis model of Example 2 which is arranged in two rows in parallel as illustrated in Fig. 11(A).

In the analytical models of Examples 2 and 7, the row spacing in the flange width direction between the two rows was 20 mm. In Example 7, the joining spacing in the material axis direction D of the joining members 20 in each row arranged in parallel in the flange width direction was set to 600 mm. Then, as in Example 2, the maximum bending strength increase rate was calculated using the reference model.

As shown in Figure 19, in Example 7, in which the joining member 20 was placed in the auxiliary position, the increase rate of the maximum bending strength was found to be greater than in Example 2, in which the joining member 20 was not placed in the auxiliary position.

(Action and effect)
In this embodiment, as shown in Figure 10, it has been found that when the multiple connecting members 20 are arranged in two parallel rows, the bending strength of the lip channel steel 12 is increased compared to when the connecting members 20 are arranged in a single row. Also, it has been found that when the multiple connecting members 20 are arranged in a staggered pattern, the bending strength of the lip channel steel 12 is increased compared to when the connecting members 20 are arranged in a single row, even if the number of connecting members 20 is the same.

In other words, when the connecting members 20 are arranged in two parallel rows or a staggered pattern, the restraining effect of the face plates 14 can be increased compared to when the connecting members 20 are arranged in a single row, thereby suppressing rotation of the lip channel steel 12 at the joining position of the joint. As a result, the occurrence of buckling of the low heat transfer steel can be delayed. Therefore, in this embodiment, even if the lip channel steel 12 used as a stud is perforated low heat transfer steel with improved thermal insulation performance, a decrease in strength due to buckling can be suppressed.

Therefore, the panel material 10 according to this embodiment can suppress the reduction in strength due to buckling, which is unique to low heat transfer steel, in the lip channel steel 12 made of low heat transfer steel with improved thermal insulation performance.

Furthermore, in this embodiment, as shown in Figure 15, when the plate thickness t is 1.6 mm or less, the connecting members 20 are arranged in two parallel rows, and the connecting spacing is 490 mm or less, a maximum bending strength increase rate of 1.10 or more can be achieved compared to a lip channel steel with connecting members 20 arranged in a single row.

Furthermore, in this embodiment, as shown in Figure 17, when the joining members 20 are arranged in two parallel rows, if the joining spacing between the joining members 20 is 650 mm or less and the lip length L is equal to or greater than the required lip length, a maximum bending strength increase rate of 1.10 or more can be achieved compared to when the joining members 20 are arranged in a single row.

In addition, in this embodiment, as shown in Figure 19, the connecting member 20 is placed at an auxiliary position set at the center position in the flange width direction of the flange 12B of the lip channel steel 12. Therefore, a larger increase in maximum bending strength can be achieved compared to when the connecting member 20 is not placed at the auxiliary position.

Furthermore, as shown in Figure 16, when the plate thickness t of the lip channel steel 12 is 1.6 mm or less, the connecting members 20 are arranged in a staggered pattern, and the connecting spacing is 200 mm or less, the maximum bending strength increase rate can be achieved to 1.10 or more compared to when the connecting members 20 are arranged in a single row.

Furthermore, in this embodiment, as shown in Figure 6, if the slit ratio, defined by dividing the sum of the slit spacings in the material axis direction of the web 12A by the sum of the slit lengths, is 5% or more and 20% or less, low heat transfer steel with ensured thermal insulation performance can be achieved.

Furthermore, the manufacturing method for the panel material according to this embodiment can provide a panel material 10 that can suppress the reduction in strength due to buckling, which is unique to low heat transfer steel, in the lip channel steel 12 made of low heat transfer steel with improved thermal insulation performance.

<Other embodiments>
Although the present disclosure has been described by the above embodiments, this description does not limit the present disclosure, and it should be understood that various alternative embodiments, examples, and operating techniques will become apparent to those skilled in the art from the present disclosure.

For example, while the present embodiment illustrates a case in which one face plate 14 is joined to the plate surface of one flange 12B, the present disclosure is not limited to this. For example, two face plates 14 may be joined to the plate surface of one flange 12B along the flange width direction with the end faces of each end in contact or close to each other. The contact area between the end faces of the two face plates 14 or the gap between the end faces forms a linear joint extending along the material axis direction D of the lip channel steel 12.

When viewing the plate surface of the flange 12B from the front, multiple joining members 20 can be arranged in two parallel rows or in a staggered pattern, sandwiching the joint between the face plates 14. Even when a joint is formed, as in this embodiment, the two face plates 14 can enhance the restraining effect, thereby suppressing rotation of the lip channel steel 12 at the joining position of the joint.

In addition, in the present disclosure, the joining area between the flange 12B and the face material 14 on the plate surface does not need to extend over the entire length of the material axis direction D, and the joining area may be partial. In addition, in the present disclosure, the panel material may include both a portion where one face material 14 is joined along the material axis direction D of the lip channel steel 12, and a portion where two face materials are joined along the flange width direction.

In addition, the present disclosure can be constructed by partially combining the configurations shown in Figures 1 to 19. The present disclosure includes various embodiments not described above, and the technical scope of the present disclosure is defined only by the invention-specific matters of the claims that are appropriate from the above description.

10 Panel material 10Z Panel material 12 Lip channel steel (frame material)
12A Web 12B Flange 12C Lip 14 Face material 16 Slit 18 Joint 20 Joint member 22 Face material 24 Filler member C Center line Dx Joint spacing D Material axis direction G Spacing HW Web height L Lip length M Slit length WF Flange width t Plate thickness δx Displacement δy Displacement

Claims (4)

a lip channel steel having a web, a pair of flanges, and a pair of lips, which improves the heat insulating performance of the channel steel and has holes in the web that cause local deformation of the web in response to a bending load applied to the flanges ;
The surface material and
a plurality of joining members for joining an outer surface of at least one of the flanges and the face material, the joining members being arranged in a staggered pattern when the plate surface of the face material is viewed from the front;
A panel material having the above structure. The plate thickness of the lip channel steel is 1.6 mm or less,
In the plurality of staggered joining members , the interval between adjacent joining members along the material axis direction of the lip channel steel is 200 mm or less.
The panel material of claim 1. the hole is a slit,
A slit ratio defined by dividing the sum of the slit intervals in the material axis direction of the lip channel steel by the sum of the slit lengths is 5% or more and 20% or less.
The panel material according to claim 1 or 2 . At least one flange of a lip channel steel having a web, a pair of flanges, and a pair of lips, which improves the heat insulating performance of the channel steel and has holes in the web that cause local deformation of the web in response to a bending load applied to the flange, is joined to a face material layered on the outer surface of at least one of the flanges by a plurality of joining members arranged in a staggered pattern when the plate surface of the face material is viewed from the front.
Manufacturing method of panel material.