H-shaped cross-sectional member and support structure

Abstract

To provide a member with an H-shaped cross section reasonably constituting a cross section shape.SOLUTION: A steel member 25 with an H-shaped cross section comprises: a first flange 26; a second flange 27; and a web 28 connecting the first flange and the second flange with each other. A plurality of plate-like members disposed at an opposite side to the web with the first flange interposed between themself and the web and arranged in a material axis direction of the member with an H-shaped cross section are respectively attached to the first flange directly or via a connection member. A width of the second flange is larger than a width of the first flange.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] This invention relates to an H-shaped cross-sectional member and a support structure. [Background technology]

[0002] H-shaped steel members are used in many building components, such as beams supporting floor slabs and roofs, purlins supporting roofs, and furring strips supporting wall materials (see, for example, Patent Documents 1 to 3). When a bending moment is generated in a supporting member due to the mass of the supported member or external forces, it is rational to use an H-shaped member as the supporting member because it has high bending performance around the strong axis relative to the weight of the steel and good cross-sectional efficiency. For this reason, H-shaped members are commonly used as supporting members. An H-shaped cross-section member consists of two flanges and a web connecting them. In an H-shaped cross-section member subjected to bending, one flange bears the compressive force and the other flange bears the tensile force. Since the magnitudes of these compressive and tensile forces are usually equal, the two flanges are generally made to have a cross-sectional shape with equal width and equal thickness. For this reason, a typical H-shaped cross-section member has a cross-section that is symmetrical with respect to an axis perpendicular to the web when viewed in the direction of the material axis of the H-shaped cross-section member. Furthermore, if the web is joined at the center of the width of each of the two flanges, the cross-section of the H-shaped cross-section member will have a biaxially symmetric shape.

[0003] Furthermore, in H-shaped cross-sectional members used as secondary beams supporting the floors of buildings, a floor slab made of concrete capable of bearing compressive load is attached to the compression side of the H-shaped cross-sectional member. In this case, the cross-sectional dimensions of the two flanges of the H-shaped cross-sectional member may differ. In this case, since the concrete bears the compressive force that would otherwise be borne by the compression-side flange of the H-shaped cross-sectional member, it is possible to reduce the cross-sectional dimensions of the compression-side flange. However, if a portion of the stress acting on an H-shaped cross-section member is to be borne by a plate-like member (face material), then a single plate-like member capable of bearing the load must be installed seamlessly along the axial direction of the H-shaped cross-section member. However, in the case of corrugated metal roofs made of thin steel sheets (multiple plate-like members), the load bearing cannot be expected to be sufficient.

[0004] Furthermore, for multiple plate-like members such as corrugated metal roofs and exterior wall materials, standard dimensions are established from the standpoint of ease of construction and transport. When multiple plate-like members are attached to an H-shaped cross-section member, the multiple plate-like members are installed in a continuous line along the material axis. As a result, there may be minute gaps between adjacent plate-like members along the material axis, and the load-bearing capacity of the plate-like members in the material axis direction cannot be expected. For this reason, the use of H-shaped cross-section members with two flanges of different cross-sectional dimensions is practically limited to cases where a concrete floor slab is attached.

[0005] The above points explain why H-shaped cross-sectional members with biaxial symmetry are commonly used in current designs. H-shaped members exhibit excellent cross-sectional properties around the strong axis, but poor cross-sectional properties around the weak axis. Therefore, lateral buckling of H-shaped members (buckling while undergoing twisting deformation and out-of-plane movement) becomes a problem. When lateral buckling occurs, a rapid deterioration in load-bearing capacity occurs, making the behavior of the H-shaped member unstable. Consequently, H-shaped members must be designed to prevent lateral buckling. Specifically, the "Ministry of Land, Infrastructure, Transport and Tourism Notification No. 1024 of 2001, which specifies special allowable stresses and special material strengths," defines the allowable stress for buckling of bending members. This notification stipulates that the allowable stress should be reduced when the length of the member over which lateral buckling may occur is long. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Patent No. 4826807 [Patent Document 2] Japanese Patent Publication No. 2020-153125 [Patent Document 3] Patent No. 6892010 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, under conditions where lateral buckling is likely to occur, such as when the length of the H-shaped cross-section member is long or the width of the H-shaped cross-section member is narrow, the allowable stress decreases, and the H-shaped cross-section member does not exhibit its inherent cross-sectional properties. Consequently, it becomes necessary to enlarge the cross-section of the H-shaped cross-section member, which increases the amount of steel required to construct the H-shaped cross-section member, resulting in an uneconomical design. In addition, as a method to prevent a decrease in allowable stress due to lateral buckling, stiffeners are sometimes installed in H-shaped section members to prevent lateral buckling. In this case, if a sufficient number of stiffeners are installed, a decrease in allowable stress will not occur, but the time and cost involved in processing and installing the stiffeners makes it uneconomical.

[0008] The present invention has been made in view of these problems, and aims to provide an H-shaped cross-sectional member with a rationally configured cross-sectional shape, and a support structure equipped with this H-shaped cross-sectional member. [Means for solving the problem]

[0009] To solve the aforementioned problems, this invention proposes the following means. The H-shaped cross section member of the present invention is a steel H-shaped cross section member comprising a first flange, a second flange, and a web that joins the first flange and the second flange to each other, wherein a plurality of plate-like members are arranged on the opposite side of the web with the first flange in between and aligned in the material axis direction of the H-shaped cross section member, and are attached to the first flange directly or via a joint member, and the width of the second flange is wider than the width of the first flange.

[0010] Generally, even if multiple plate-like members are attached directly or via joint members to the first flange of a steel H-shaped cross section member, positioned on the opposite side of the web with the first flange in between and aligned in the direction of the material axis, it is considered that these multiple plate-like members cannot be expected to bear the in-plane bending strength required of the H-shaped cross section member. In this invention, the inventors, after diligent study, have found that even when the first flange is attached to multiple plate-shaped members that cannot be expected to bear load, the elastic buckling resistance of the H-shaped cross section member of the present invention is greater when, for example, the sum of the cross-sectional areas of both flanges perpendicular to the material axis direction is constant, compared to when the widths of both flanges are equal, if the width of the second flange is wider than the width of the first flange. Therefore, by making the width of the second flange wider than the width of the first flange, the elastic buckling resistance of the H-shaped cross-sectional member increases, allowing for a rational configuration of the cross-sectional shape of the H-shaped cross-sectional member.

[0011] Furthermore, another H-shaped cross section member of the present invention is a steel H-shaped cross section member comprising a first flange, a second flange, and a web that joins the first flange and the second flange to each other, wherein a plurality of plate-like members are arranged on the opposite side of the web with the first flange in between and aligned in the material axis direction of the H-shaped cross section member, and are attached to the first flange directly or via a joint member, and the thickness of the second flange is greater than the thickness of the first flange. In this invention, the inventors, after diligent study, have found that even when the first flange is attached to multiple plate-shaped members that cannot be expected to bear load, the elastic buckling resistance of the H-shaped cross section member of the present invention is greater when the thickness of the second flange is greater than the thickness of the first flange, for example, when the sum of the cross-sectional areas of both flanges perpendicular to the material axis direction is constant, compared to when the thicknesses of both flanges are equal. Therefore, by making the thickness of the second flange greater than the thickness of the first flange, the elastic buckling resistance of the H-shaped cross-sectional member increases, allowing for a rational configuration of the cross-sectional shape of the H-shaped cross-sectional member.

[0012] In addition, in the H-shaped cross-sectional member, the plurality of plate-like members may form a roofing material. In this invention, by attaching the first flange directly to the roofing material or via a joint member, the roofing material can be supported by the H-shaped cross-sectional member.

[0013] In addition, in the H-shaped cross-sectional member, the plurality of plate-like members may form an exterior wall material. In this invention, by attaching the first flange directly to the exterior wall material or via a joint member, the exterior wall material can be supported by the H-shaped cross-sectional member.

[0014] In addition, in the H-shaped cross-sectional member, it may be a welded lightweight H-shaped steel manufactured by continuous high-frequency resistance welding from a steel strip or a combination of this and high-frequency induction welding. In this invention, the H-shaped cross-sectional member can be configured relatively lightly with the welded lightweight H-shaped steel.

[0015] In addition, the support structure of the present invention is characterized by including the H-shaped cross-sectional member described above and the plurality of plate-like members. In this invention, a support structure can be configured using an H-shaped cross-sectional member with a reasonably configured cross-sectional shape.

Effects of the Invention

[0016] In the H-shaped cross-sectional member and the support structure of the present invention, the cross-sectional shape can be reasonably configured.

Brief Description of the Drawings

[0017] [Figure 1] It is a perspective view of a part of a building in which the H-shaped cross-sectional member and the support structure of an embodiment of the present invention are used, broken. [Figure 2] It is a perspective view of a second H-shaped cross-sectional member. [Figure 3] It is a cross-sectional view of the same second H-shaped cross-sectional member. [Figure 4] It is a diagram showing an example of an antisymmetric bending moment assuming an earthquake. [Figure 5]This figure shows an example of the bending moment due to the load under normal use. [Figure 6] This diagram shows the change in elastic buckling resistance with respect to the (L / H) value when the first flange is not restrained during an earthquake in the H-400. [Figure 7] This diagram shows the change in elastic buckling resistance with respect to the (L / H) value when the first flange is not restrained during an earthquake in the H-900. [Figure 8] This figure shows the change in elastic buckling resistance with respect to the (L / H) value when the lateral movement of the first flange is restrained during an earthquake in the H-400. [Figure 9] This figure shows the change in elastic buckling resistance with respect to the (L / H) value when the lateral movement of the first flange is restrained during an earthquake in the H-900. [Figure 10] This figure shows the change in elastic buckling resistance with respect to the (L / H) value when the first flange is not restrained during normal use in the H-400. [Figure 11] This diagram shows the change in elastic buckling resistance with respect to the (L / H) value when the first flange is not restrained during normal use with the H-900. [Figure 12] This figure shows the change in elastic buckling resistance with respect to the (L / H) value when the lateral movement of the first flange is restrained during normal use in the H-400. [Figure 13] This figure shows the change in elastic buckling resistance with respect to the (L / H) value when the lateral movement of the first flange is restrained during normal use in the H-900. [Figure 14] This diagram shows the change in elastic buckling resistance with respect to the (L / H) value when the first flange is not restrained during an earthquake. [Figure 15] This figure shows the change in elastic buckling resistance with respect to the (L / H) value when the lateral movement of the first flange is restrained during an earthquake. [Figure 16] This figure shows the change in elastic buckling resistance with respect to the (L / H) value when the first flange is not restrained during normal use. [Figure 17]This figure shows the change in elastic buckling resistance with respect to the (L / H) value when the lateral movement of the first flange is restrained during normal use. [Figure 18] This figure shows the change in elastic buckling resistance with respect to the (L / H) value when the lateral movement of the first flange is restrained and the warping of the first and second flanges is restrained during an earthquake. [Figure 19] This figure shows the change in elastic buckling strength with respect to the (L / H) value when the lateral movement of the first flange is restrained under wind load negative pressure and both ends in the axial direction of the material are pin-jointed. [Figure 20] This figure shows an example of a bending moment assuming negative pressure due to wind load. [Figure 21] This diagram illustrates the change in cross-sectional efficiency with respect to the width of the second flange when the lateral movement of the first flange is restrained during an earthquake. [Figure 22] This diagram shows the change in cross-sectional efficiency with respect to the width of the second flange when the lateral movement of the first flange is restrained during normal use. [Figure 23] This is a schematic diagram illustrating the stiffening effect of a plate-shaped member on an H-shaped cross-section member. [Figure 24] This figure illustrates an example of the change in cross-sectional efficiency with respect to the width of the second flange when the lateral movement of the first flange is restrained by a spring during an earthquake. [Figure 25] This figure illustrates another example of the change in cross-sectional efficiency with respect to the width of the second flange when the lateral movement of the first flange is spring-restrained during an earthquake. [Figure 26] This figure illustrates an example of the change in cross-sectional efficiency with respect to the width of the second flange when the lateral movement of the first flange is spring-restrained during normal operation. [Figure 27] This figure illustrates another example of the change in cross-sectional efficiency with respect to the width of the second flange when the lateral movement of the first flange is spring-restrained during normal operation. [Figure 28] This is a perspective view showing a section of a building in which a support structure of a first modified example of one embodiment of the present invention is used. [Figure 29] This is a perspective view showing a section of a building in which a support structure of a second variant of one embodiment of the present invention is used, with the section fractured. [Modes for carrying out the invention]

[0018] Hereinafter, an embodiment of the H-shaped cross-sectional member and support structure according to the present invention will be described with reference to Figures 1 to 29.

[0019] [1. Structure of buildings using H-shaped cross-sectional members and support structures] The H-shaped cross-sectional members 15, 25 and support structures 46, 47 described later in this embodiment are used in the building 1 shown in Figure 1. The building 1 comprises a plurality of columns 10, a plurality of first H-shaped cross-sectional members (H-shaped cross-sectional members) 15 which are main beams, a plurality of second H-shaped cross-sectional members (H-shaped cross-sectional members) 25 which are secondary beams, and a folded plate roof 35. The columns 10 extend vertically. Multiple columns 10 are arranged at intervals from each other. The columns 10 are made of steel, reinforced concrete (RC), steel reinforced concrete (SRC), etc.

[0020] The first H-shaped cross-sectional member 15 and the second H-shaped cross-sectional member 25 are made of steel. The first H-shaped cross section member 15 comprises a first flange 16, a second flange 17, and a web 18. The first flange 16, the second flange 17, and the web 18 are each formed from steel plates. The first flange 16 and the second flange 17 are each arranged along a horizontal plane and face each other in the vertical direction. The first flange 16 is positioned above the second flange 17. The web 18 is positioned between the first flange 16 and the second flange 17. The web 18 joins the widthwise centers of the first flange 16 and the widthwise centers of the second flange 17 to each other.

[0021] Gusset plates (not shown) are attached to the web 18, etc., of the first H-shaped cross section member 15, which is the main beam, by welding or other means. The first H-shaped cross-sectional member 15 spans between adjacent columns 10 and extends in a direction along the horizontal plane. Both ends of the first H-shaped cross-sectional member 15 are joined to the columns 10 by welding or other means.

[0022] As shown in Figures 1 to 3, the second H-shaped cross section member 25 comprises a first flange 26, a second flange 27, and a web 28. The first flange 26, the second flange 27, and the web 28 are each formed from steel plates. The first flange 26 and the second flange 27 are each arranged along a horizontal plane and face each other in the vertical direction. The first flange 26 is positioned above the second flange 27. The web 28 is positioned between the first flange 26 and the second flange 27. The web 28 joins the widthwise centers of the first flange 26 and the widthwise centers of the second flange 27 to each other. The cross-sectional shapes of the H-shaped members 15 and 25 perpendicular to the material axis are both H-shaped. The orientation in which the H-shaped cross-sectional members 15 and 25 are arranged is not limited thereto. The second H-shaped cross-sectional member 25 and the first H-shaped cross-sectional member 15 may be rolled H-shaped steel or welded H-shaped steel.

[0023] Here, as shown in Figure 3, the dimensions of the second H-shaped cross-sectional member 25 are defined. Let the width of the first flange 26 be B1 (mm). Let the thickness of the first flange 26 be t f1 (mm) Let the width of the second flange 27 be B2 (mm). Let the thickness of the second flange 27 be t f2 (mm) Let the thickness of web 28 be t w Let (mm) be the height of the second H-shaped cross section member 25 be H (mm). In the second H-shaped cross-sectional member 25, the cross-sectional area perpendicular to the material axis direction of the second H-shaped cross-sectional member 25 is A (mm²). 2 ) As shown in Figure 2, the length of the second H-shaped cross-sectional member 25 is denoted as L (mm).

[0024] As shown in Figure 1, the second H-shaped cross-sectional member 25 spans between the opposing first H-shaped cross-sectional members 15 and extends in a direction along the horizontal plane. Both ends of the second H-shaped cross-sectional member 25 in the direction of the material axis are connected to the gusset plate of the first H-shaped cross-sectional member 15 by high-strength bolts or the like (not shown).

[0025] The corrugated metal roof 35 is a roofing material. For example, the corrugated metal roof 35 is constructed by bending a metal sheet. The corrugated metal roof 35 is constructed by arranging multiple corrugated members 36 that extend in a first horizontal direction U along the horizontal plane, and in a second horizontal direction V that is perpendicular to the first horizontal direction U and also along the horizontal plane. The corrugated member 36 has a bottom plate 37, a first inclined plate 38, a top plate 39, and a second inclined plate 40. The bottom plate 37, the first inclined plate 38, the top plate 39, and the second inclined plate 40 are each plate-shaped members (surface materials).

[0026] The base plate 37 and the top plate 39 are arranged to follow the horizontal plane. The top plate 39 is positioned above the base plate 37. The first inclined plate 38 is inclined so as it approaches the first side V1 in the second horizontal direction V of the base plate 37, it gradually slopes upward. The top plate 39 extends from the end of the first side V1 of the first inclined plate 38 toward the first side V1. The second inclined plate 40 is inclined from the end of the first side V1 of the top plate 39 toward the first side V1, gradually sloping downwards as it approaches the first side V1. The second inclined plate 40 is connected to the end of the second side V2 in the second horizontal direction V, which is opposite to the first side V1, of the bottom plate 37 of the corrugated member 36 adjacent to the first side V1.

[0027] The corrugated metal roof 35 is positioned on the opposite side (above) of the web 18 in the first H-shaped cross section member 15, with the first flange 16 in between. The bottom plate 37, first inclined plate 38, top plate 39, and second inclined plate 40 of the corrugated plate roof 35 are positioned on the opposite side (above) of the web 28 with the first flange 26 in between in the second H-shaped cross section member 25, and are aligned in the second horizontal direction V, which is the material axis direction of the second H-shaped cross section member 25. The bottom plate 37 of the corrugated metal roof 35 is supported from below by the first flange 16 of the first H-shaped cross section member 15 and the first flange 16 of the second H-shaped cross section member 25. In this example, the bottom plate 37, the first inclined plate 38, the top plate 39, and the second inclined plate 40 of the corrugated metal roof 35 are attached to the first flanges 16 and 26 of the H-shaped cross section members 15 and 25, respectively, via joint members (not shown) such as known fittings and fastening members.

[0028] Furthermore, the first H-shaped cross-sectional member 15 and the corrugated roof 35 constitute the support structure 46. The second H-shaped cross-sectional member 25 and the corrugated roof 35 constitute the support structure 47. The bottom plate 37, first inclined plate 38, top plate 39, and second inclined plate 40 of the corrugated plate roof 35 may be directly attached to the first flanges 16 and 26 of the H-shaped cross section members 15 and 25, respectively.

[0029] Below, we will explain the results of our investigation into the effects of the width and thickness of flanges 26 and 27, using the second H-shaped cross-sectional member 25 of the H-shaped cross-sectional members 15 and 25 as an example.

[0030] [2. Examination of the effect of flange width on the support structure] The lateral buckling behavior of a second H-shaped cross section member 25 (hereinafter also simply referred to as H-shaped cross section member 25) in which the widths of flanges 26 and 27 are equal, and the lateral buckling behavior of an H-shaped cross section member 25 in which the widths of flanges 26 and 27 are different, was investigated using the Finite Element Method (FEM). Figure 2 shows the analytical model of the H-shaped cross-section member 25. In the analytical model, the H-shaped cross-section member 25 is constructed using four-node shell elements. The x-axis is defined in the direction of the material axis of the H-shaped cross-section member 25. The y-axis is defined in the direction in which the flanges 26 and 27 face each other, and the z-axis is defined in the thickness direction of the web 28.

[0031] When a plate-shaped member is attached to the first flange 26, the z-axis movement (lateral movement) of the node at position 26a, which is the cross-sectional center of the upper first flange 26 in Figure 2, is constrained (dz(uz, displacement due to z-axis movement) = 0). When a plate-shaped member is not attached to the first flange 26, the z-axis movement of the node at position 26a of the first flange 26 is not constrained. Furthermore, both ends of the H-shaped cross-section member 25 in the direction of the material axis were fixed ends with respect to the twisting of the H-shaped cross-section member 25, and free ends with respect to the curvature of the flanges 26 and 27. Specifically, at the first end 25a of the H-shaped cross-section member 25 in the direction of the material axis, dx=0, dy=0, dz=0, and rotx (rotation around the x-axis)=0. At the second end 25b of the H-shaped cross-section member 25, opposite to the first end 25a in the direction of the material axis, dy=0, dz=0, and rotx=0.

[0032] For this analytical model, an elastic buckling analysis (eigenvalue analysis) was performed on the H-shaped cross section member 25 in the case where a bending moment acts on it due to a bending moment around the z-axis at the end in the axial direction of the material, and a distributed load in the y-axis direction at the first flange 26. Furthermore, the first flange 26 may be positioned below the second flange 27, or the flanges 26 and 27 may be arranged side by side along a horizontal plane. In other words, the orientation in which the H-shaped cross-section member 25 is positioned is not limited to these.

[0033] Next, we will explain each case in the analysis model. Here, parameters are varied by changing the width of flanges 26 and 27, based on H-beams defined by JIS standards: H-400x200x8x13 (hereinafter referred to as H-400) and H-900x300x16x28 (hereinafter referred to as H-900). Table 1 shows a list of the cases analyzed. Note that the thickness of flanges 26 and 27 are equal.

[0034] [Table 1]

[0035] For cases a100 to a300, which are H-400, the width of flanges 26 and 27 is changed in 50mm increments, and for cases b100 to b500, which are H-900, the width of flanges 26 and 27 is changed in 100mm increments. For H-400 and H-900, no other cross-sectional dimensions have been changed. Furthermore, if the width of the second flange 27 is widened, the width of the first flange 26 is narrowed by the same amount as the widening of the second flange 27. If the width of the second flange 27 is narrowed, the width of the first flange 26 is widened by the same amount. In other words, even when the widths of flanges 26 and 27 are changed, the cross-sectional area A of the H-shaped cross-sectional member 25 is equivalent to the cross-sectional area A of cases a200 and b300, where the widths of the standard flanges 26 and 27 are equal. The mass per unit length of the H-shaped cross-sectional member 25 is also equivalent to the mass per unit length of cases 200a and b300. For each case, we analyzed the scenarios in which two types of bending moments act: an inversely symmetric bending moment simulating an earthquake, and a bending moment due to live load simulating normal use. We varied the length L of the H-shaped cross section member 25 within the range of 6 to 50, considering the case where L is applied.

[0036] Figure 4 shows an example of an inversely symmetric bending moment assuming an earthquake, and Figure 5 shows an example of a bending moment due to a live load assuming normal use. In Figures 4 and 5, the horizontal axis represents the dimensionless coordinates of the H-shaped cross-section member 25 in the direction of the material axis, and the vertical axis represents the dimensionless bending moment acting on the H-shaped cross-section member 25. The dimensionless coordinates are the ratio of the coordinates (x-coordinate) of the H-shaped cross-section member 25 in the direction of the material axis to the length L. The dimensionless bending moment is the ratio of the bending moment acting on each position of the H-shaped cross-section member 25 in the direction of the material axis to the maximum value of the absolute value of the bending moment acting on the H-shaped cross-section member 25.

[0037] Figures 6 to 9 show the eigenvalue analysis results when an inversely symmetric bending moment, simulating an earthquake, is applied. Figures 6 and 7 show the case where the first flange 26 is not constrained, while Figures 8 and 9 show the case where the lateral movement (movement in the z-axis direction) of the first flange 26 is constrained. In the following figures, the vertical axis represents the elastic buckling resistance obtained from eigenvalue analysis, and the horizontal axis represents the ratio (L / H) of the length L of the H-shaped cross section member 25 to the height H of the H-shaped cross section member 25.

[0038] Figures 10 to 13 show the eigenvalue analysis results when a bending moment due to a load, simulating normal use, is applied. Figures 10 and 11 show the case where the first flange 26 is not constrained, while Figures 12 and 13 show the case where the lateral movement of the first flange 26 is constrained.

[0039] As shown in Figures 6 and 7, when the first flange 26 is not restrained during an earthquake, changing the widths of flanges 26 and 27 from equal to different widths reduces the elastic buckling resistance. Similarly, in the normal operating conditions shown in Figures 10 and 11, changing the widths of flanges 26 and 27 from equal to different widths reduces the elastic buckling resistance. In other words, regardless of the load conditions during earthquakes or normal operating conditions, when the first flange 26 is not restrained, using cross-sections with different widths for flanges 26 and 27 leads to a reduction in elastic buckling resistance and an inefficient design. On the other hand, when the lateral movement of the first flange 26 is restrained as shown in Figures 8, 9, 12, and 13, regardless of the load conditions during an earthquake or normal use, widening the width of the second flange 27 and narrowing the width of the first flange 26 results in a greater elastic buckling resistance than when the widths of flanges 26 and 27 are equal. When narrowing the width of the second flange 27 and widening the width of the first flange 26 results in a smaller elastic buckling resistance than when the widths of flanges 26 and 27 are equal.

[0040] In other words, under conditions where the lateral movement of the first flange 26 is restrained, by using a cross-section where the width of the second flange 27 is wider and the width of the first flange 26 is narrower, it is possible to achieve a higher lateral buckling resistance (elastic buckling resistance) with the same amount of steel material as a cross-section where the widths of the flanges 26 and 27 are equal. This trend is observed in both the H-400 and H-900 models even when the cross-sectional dimensions of the H-shaped cross-sectional member 25 are changed, suggesting that the same trend is observed for all H-shaped cross-sectional members 25. In other words, under conditions where the lateral movement of the first flange 26 is constrained, using an asymmetrical H-shaped cross section member 25 in which the width of the second flange 27 is wider than the width of the first flange 26 allows for a reduction in the amount of steel required to achieve a certain lateral buckling resistance compared to the case where the widths of flanges 26 and 27 are equal, thus enabling a more efficient design.

[0041] In Figures 8 and 9, the elastic buckling strength plateaus in the case where the width of the second flange 27 is wide when the (L / H) value is small because the H-shaped cross section member 25 undergoes local buckling. This is due to a buckling phenomenon different from the lateral buckling targeted by the present invention. Local buckling occurs when the lateral buckling strength is sufficiently large, and the strength due to this local buckling also occurs in a region that is sufficiently large compared to the yield strength of the H-shaped cross section member 25, so it does not pose a problem. On the other hand, if flanges 26 and 27 are extremely thin, local buckling may become a problem. For this reason, it is preferable that the width-to-thickness ratio of flanges 26 and 27 be 15.5√(235 / F) or less, which is the specified value for beam member type FC according to Article 3 of Notification No. 1792 of 1980. However, F is the standard strength of the H-shaped section member 25.

[0042] [3. Examination of the effect of flange thickness in the support structure] Next, we will describe the analysis cases for elastic buckling analysis using the thickness of flanges 26 and 27 as variables. Here, the parameters are varied by changing the thickness of flanges 26 and 27 based on the cross-sectional dimensions of H-400x200x8x13. Table 2 shows a list of the cases to be analyzed. Note that the widths of flanges 26 and 27 are equal to each other.

[0043] [Table 2]

[0044] Here, the thicknesses of flanges 26 and 27 are changed in 3mm increments, while other cross-sectional dimensions remain unchanged. Note that if the thickness of the second flange 27 is increased, the thickness of the first flange 26 is decreased by the same amount; conversely, if the thickness of the second flange 27 is decreased, the thickness of the first flange 26 is increased by the same amount. In other words, even when the thickness of flanges 26 and 27 is changed, the cross-sectional area A of the H-shaped cross-sectional member 25 is equivalent to the cross-sectional area A of case c13, where the thicknesses of the standard flanges 26 and 27 are equal. The mass per unit length of the H-shaped cross-sectional member 25 is also equivalent to the mass per unit length of case c13. For each case, we analyzed the case where two types of bending moments act: an inversely symmetric bending moment assuming an earthquake, and a bending moment due to live load assuming normal use, by changing the length L within the range of 6 to 50 for the (L / H) ratio.

[0045] Figures 14 and 15 show the eigenvalue analysis results when an inversely symmetric bending moment is applied, simulating an earthquake. Figure 14 shows the case where the first flange 26 is not constrained, and Figure 15 shows the case where the lateral movement of the first flange 26 is constrained. Figures 16 and 17 show the eigenvalue analysis results when a bending moment due to a load, simulating normal use, is applied. Figure 16 shows the case where the first flange 26 is not constrained, and Figure 17 shows the case where the lateral movement of the first flange 26 is constrained.

[0046] Figure 14 shows that when the first flange 26 is not restrained during an earthquake, changing the thickness of flanges 26 and 27 does not significantly alter the elastic buckling strength. Figure 16 shows that under normal use, increasing the thickness of the second flange 27 results in a lower elastic buckling strength, while decreasing the thickness of the second flange 27 results in a higher elastic buckling strength. In other words, when the first flange 26 is not restrained, increasing the thickness of the second flange 27 and decreasing the thickness of the first flange 26 tends to result in the same or even lower elastic buckling strength compared to when flanges 26 and 27 have equal thickness, leading to an inefficient design. On the other hand, in the case where the lateral movement of the first flange 26 is restrained during earthquakes and normal use as shown in Figures 15 and 17, increasing the thickness of the second flange 27 and decreasing the thickness of the first flange 26 results in a greater elastic buckling resistance than when the thicknesses of flanges 26 and 27 are equal. Conversely, decreasing the thickness of the second flange 27 and increasing the thickness of the first flange 26 results in a smaller elastic buckling resistance than when the thicknesses of flanges 26 and 27 are equal.

[0047] In other words, regardless of the load conditions during an earthquake or normal use, under conditions where the lateral movement of the first flange 26 is restrained, by using a cross-section where the thickness of the second flange 27 is thicker and the thickness of the first flange 26 is thinner, and where the thicknesses of flanges 26 and 27 are different, a higher elastic buckling resistance can be achieved with the same amount of steel as with a cross-section where the thicknesses of flanges 26 and 27 are equal. That is, under conditions where the lateral movement of the first flange 26 is restrained, using an asymmetrical H-shaped cross-section member 25 in which the thickness of the second flange 27 is thicker than the thickness of the first flange 26 allows for a smaller amount of steel to be used to achieve a certain elastic buckling resistance compared to the case where the thicknesses of flanges 26 and 27 are equal, enabling a more efficient design.

[0048] In Figures 14 and 15, the elastic buckling strength plateaus in some analysis cases when the (L / H) value is small because of local buckling of the thin flange. This is due to a buckling phenomenon different from the lateral buckling targeted by this invention. As with Figures 8 and 9, local buckling occurs when the lateral buckling strength is sufficiently large. The strength due to this local buckling also occurs in a region that is sufficiently large compared to the yield strength of the H-shaped cross section member 25, and therefore does not pose a problem. On the other hand, if flanges 26 and 27 are extremely thin, local buckling may become a problem. For this reason, it is preferable that the width-to-thickness ratio of flanges 26 and 27 be 15.5√(235 / F) or less, which is the specified value for beam member type FC according to Article 3 of Notification No. 1792 of 1980.

[0049] [4. Examination of the effects of the degree of fixation and bending moment distribution at the ends of H-shaped cross-section members] The previous studies focused on a model in which the flanges 26 and 27 at the material axis ends of the H-shaped cross-section member 25 were considered free ends, and a bending moment about the z-axis was applied to these material axis ends. Below, we will examine five cases for H-400 shown in Table 1, including conditions with different degrees of fixation and bending moment distributions at the material axis ends of the H-shaped cross-section member 25. Figure 18 shows the analysis results when the curvature of flanges 26 and 27 at the ends in the material axis direction is fixed, and an inversely symmetric bending moment, simulating an earthquake, is applied. Figure 19 shows the analysis results when the ends in the material axis direction are pin-jointed, and no bending moment about the z-axis is applied at the ends in the material axis direction, and only a distributed load in the y-axis direction, simulating negative pressure due to wind load, is applied to the first flange 26. In both Figure 18 and Figure 19, it is assumed that the lateral movement of the first flange 26 is constrained. Figure 20 shows an example of a bending moment assuming negative pressure due to wind load.

[0050] Under the conditions shown in both Figure 18 and Figure 19, similar to the analysis results described above, when the lateral movement of the first flange 26 is constrained, using a cross-section where the width of the second flange 27 is wider and the width of the first flange 26 is narrower, and where the widths of flanges 26 and 27 are different, allows for higher elastic buckling resistance with the same amount of steel as a cross-section where the widths of flanges 26 and 27 are equal. Therefore, in the present invention, similar effects can be expected even under conditions where the degree of fixation of the material axial end and the bending moment distribution differ.

[0051] [5. Examination of the relationship between the width of the second flange and section efficiency] Figures 21 and 22 show the relationship between the width of the second flange 27 and the cross-sectional efficiency, based on the elastic buckling analysis results for the first flange 26 shown in Figures 8, 9, 12, and 13 when the (L / H) value is 20. In Figures 21 and 22, the vertical axis represents the cross-sectional efficiency (the value obtained by dividing the elastic buckling strength by the mass per unit length of the H-shaped cross-sectional member 25), and the horizontal axis represents the width of the second flange 27. Figures 21 and 22 show that the value on the vertical axis increases as the width of the second flange 27 increases, indicating a greater elastic buckling resistance relative to the steel material. Therefore, from the viewpoint of elastic buckling resistance, when the lateral movement of the first flange 26 is restrained, a significant improvement in cross-sectional efficiency can be expected by minimizing the width of the first flange 26 and maximizing the width of the second flange 27.

[0052] On the other hand, the width of the first flange 26 needs to be at least 40 mm from the standpoint of ease of construction when attaching multiple plate-like members such as the corrugated roof 35 and floor, and depending on the installation position of the H-shaped cross section member 25, at least 100 mm is required to ensure safety during construction. Furthermore, in the H-shaped cross section member 25, from the viewpoint of cross-sectional efficiency around the strong axis, the widths of the flanges 26 and 27 are generally set to be equal to or less than the height H of the H-shaped cross section member 25. Even when the widths of the flanges 26 and 27 are different, it is preferable that the width of the second flange 27 is less than or equal to the height H.

[0053] [6. Examination of the case where the lateral movement of the first flange is restrained by an elastic spring] Next, an elastic buckling analysis is performed when the lateral movement of the first flange 26 is restrained by an elastic spring. Previous analysis results showed that the lateral movement of the first flange 26 was completely restrained. However, in reality, the restraint is elastic spring-like, corresponding to the rigidity of the plate-shaped member attached to the first flange 26. Figure 23 shows a schematic diagram of the stiffening effect of the plate-shaped member 50 on the H-shaped cross section member 25 that undergoes lateral buckling. In Figure 23, the plate-shaped member 50 is shown by a dashed line. Hereafter, the H-shaped cross section member 25 that is subject to lateral buckling will also be referred to as the H-shaped cross section member 25A. In Figure 23, the shape of the H-shaped cross section member 25A after lateral buckling deformation is shown by the dashed line L1. The H-shaped cross-sectional member 25 also corresponds to the main beam.

[0054] When a plate-shaped member 50 is attached to an H-shaped cross section member 25A that may experience lateral buckling, the load is transmitted to the surrounding members as a resistance mechanism due to the axial stiffness, shear stiffness, and shear stiffness of the plate-shaped member 50. However, for simplicity, we will consider only the axial stiffness of the plate-shaped member 50 in this conservative analysis. We will use axial stiffness that assumes the load is transmitted to members adjacent to the target H-shaped cross section member 25A via the plate-shaped member 50 (for example, an H-shaped cross section member 25 adjacent to the H-shaped cross section member 25A (hereinafter also referred to as H-shaped cross section member 25B)). The stiffening stiffness provided by the plate-shaped member 50 is conceptually represented as a spring 51. The spring 51 connects the H-shaped cross section member 25A and the H-shaped cross section member 25B. Here, we assume a corrugated metal roof as an example of a plate-like member 50, roughly calculate the spring stiffness, and set it as an analysis condition. There are various types of corrugated metal roofs, but here we assume a simple one made of a single relatively thin 0.6 mm steel plate. We ignore the peak and valley shape of the corrugated metal roof and consider it as a flat steel plate. Then, we roughly evaluate the stiffening K due to the corrugated metal roof using equation (1).

[0055]

number

[0056] However, E is the Young's modulus (N / mm 2 ) of the plate-like member 50, t p is the thickness (mm) of the plate-like member 50, and l p is the length (mm) of the plate-like member 50 contributing to the rigidity. For example, the length l p is the distance to the adjacent member, that is, the distance between the H-shaped cross-section members 25A and 25B. Assuming the length l p is 2.5 m, and the thickness t p is 0.6 mm, from equation (1), the supplementary rigidity K for the deformation in the direction orthogonal to the H-shaped cross-section member 25 of the folded-plate roof is 98.4 N / mm 2 . Hereinafter, this supplementary rigidity K will be approximated as 100 N / mm 2 and handled.

[0057] The analysis was targeted at the 10 cases of the H-shaped cross-section members 25 shown in Table 1. The spring rigidity was varied in 5 types. Three of the 5 types are those with the spring rigidity being the aforementioned 100 N / mm 2 , 1 / 10 thereof, and 1 / 100 thereof, that is, 10 N / mm 2 and 1 N / mm 2 . The remaining two of the 5 types are those with the spring rigidity being infinite, which completely restrains the lateral movement of the first flange 26, and those with the spring rigidity being 0, which does not restrain the lateral movement of the first flange 26. Examinations were conducted on the restraint conditions of the first flange 26 with the above 5 types of spring rigidities.

[0058] From FIG. 24 to FIG. 27, for the case where the value of (L / H) is 20, the relationship between the width of the second flange 27 and the sectional efficiency is shown. In FIGS. 24 to 27, the vertical axis represents the sectional efficiency, and the horizontal axis represents the width of the second flange 27. From FIGS. 24 to 27, the result with the spring rigidity being 100 N / mm 2 has a sectional efficiency almost equivalent to the result of completely restraining the lateral movement of the first flange 26. Therefore, the restraint by the plate-like member 50 can be regarded as lateral movement restraint. Furthermore, the spring stiffness is set to 1 / 10, or 10 N / mm 2 Even in this case, the decrease in cross-sectional efficiency is limited compared to when lateral movement is completely restrained. Regardless of whether the rigidity of the attached plate-like member is somewhat low, the width of the second flange 27 can be increased to create an H-shaped cross-sectional member 25 with good cross-sectional efficiency against lateral buckling.

[0059] Furthermore, the spring stiffness is set to 1 / 100, which is 1 N / mm 2 In this case, the cross-sectional efficiency decreases compared to when lateral movement is completely restrained. However, when the width of the second flange 27 is widened from a cross-section where the widths of flanges 26 and 27 are equal, the cross-sectional efficiency improves. In other words, even if an extremely low-rigidity plate-like member is attached, widening the width of the second flange 27 can be expected to create an H-shaped cross-sectional member 25 with good cross-sectional efficiency against lateral buckling.

[0060] [7. Effects of this embodiment] As described above, in the H-shaped cross section member 25 of this embodiment, the width of the second flange 27 may be wider than the width of the first flange 26. Generally, even if multiple plate-like members are attached directly or via joint members to the first flange of a steel H-shaped cross section member, positioned on the opposite side of the web with the first flange in between and aligned in the direction of the material axis, it is considered that these multiple plate-like members cannot be expected to bear the in-plane bending strength required of the H-shaped cross section member. As a result of diligent research, the inventors have found that even when the first flange 26 is attached to a corrugated metal roof 35 that cannot be expected to bear load, the elastic buckling resistance of the H-shaped cross section member 25 of this embodiment is greater when, for example, the sum of the cross-sectional areas of both flanges 26 and 27 perpendicular to the material axis direction is constant, compared to when the widths of both flanges 26 and 27 are equal, if the width of the second flange 27 is wider than the width of the first flange 26. Therefore, the width of the second flange 27 is wider than the width of the first flange 26, and the elastic buckling resistance of the H-shaped cross section member 25 is increased, which allows for a rational configuration of the cross-sectional shape of the H-shaped cross section member 25.

[0061] Furthermore, in the H-shaped cross-sectional member 25 of this embodiment, the thickness of the second flange 27 may be greater than the thickness of the first flange 26. As a result of diligent research, the inventors have found that even when the first flange 26 is attached to a corrugated metal roof 35 that cannot be expected to bear load, for example, when the sum of the cross-sectional areas of both flanges 26 and 27 perpendicular to the material axis direction is constant, the elastic buckling resistance of the H-shaped cross section member 25 of this embodiment is greater when the thickness of the second flange 27 is greater than the thickness of the first flange 26, compared to when the thicknesses of both flanges 26 and 27 are equal. Therefore, since the thickness of the second flange 27 is greater than the thickness of the first flange 26, the elastic buckling resistance of the H-shaped cross section member 25 is increased, allowing the cross-sectional shape of the H-shaped cross section member 25 to be rationally configured.

[0062] The multiple plate-like members, which are the base plate 37, the first inclined plate 38, the top plate 39, and the second inclined plate 40, constitute the roofing material. Therefore, by attaching the first flange 26 to the roofing material via a joint member, the roofing material can be supported by the H-shaped cross section member 25. Furthermore, in the support structures 46 and 47 of this embodiment, the support structures 46 and 47 can be constructed using H-shaped cross-sectional members 15 and 25 whose cross-sectional shapes are rationally configured. The effect of the H-shaped cross-sectional member 25 also applies to the first H-shaped cross-sectional member 15.

[0063] [8. Other Considerations] The H-shaped cross-sectional member 25 and the support structures 46 and 47 of this embodiment can be modified in various ways, as described below. The plate-like members are not particularly limited, as long as they are members other than floor slabs. Generally, in the case of floor slabs, concrete is poured at the construction site to construct a single surface material along the entire length of the H-shaped cross section member, so it can be expected to bear the in-plane bending strength required of the H-shaped cross section member. On the other hand, for members other than floor slabs, a surface is generally constructed at the construction site by arranging multiple plate-like members of standard dimensions, manufactured in a factory, in the direction of the material axis of the H-shaped cross section member. For this reason, even if a plate-like member other than a floor slab, which is positioned on the opposite side of the web with the first flange in between, is attached to the first flange of a steel H-shaped cross section member, either directly or via a joint member, it is considered that this plate-like member cannot be expected to bear the strength required of the H-shaped cross section member. In this case, the plate-like member is positioned on the opposite side of the web 28 with the first flange 26 in between. For example, the width of the second flange 27 is wider than the width of the first flange 26. As a result of diligent research, the inventors found that even when the first flange 26 is attached to a plate-shaped member that cannot be expected to bear load, the elastic buckling resistance of the H-shaped cross section member 25, in which the width of the second flange 27 is wider than the width of the first flange 26, is greater than when the widths of the two flanges 26 and 27 are equal, for example, when the sum of the cross-sectional areas of both flanges 26 and 27 perpendicular to the material axis direction is constant. Therefore, the width of the second flange 27 is wider than the width of the first flange 26, and the elastic buckling resistance of the H-shaped cross section member 25 is increased, which allows for a rational configuration of the cross-sectional shape of the H-shaped cross section member 25.

[0064] Furthermore, in the above modified example, the thickness of the second flange 27 may be greater than the thickness of the first flange 26. As a result of diligent research, the inventors found that even when the first flange 26 is attached to a plate-shaped member that cannot be expected to bear load, the elastic buckling resistance of the H-shaped cross section member 25, in which the thickness of the second flange 27 is greater than the thickness of the first flange 26, is greater than when the thicknesses of the two flanges 26 and 27 are equal, for example, when the sum of the cross-sectional areas of both flanges 26 and 27 perpendicular to the material axis direction is constant. Therefore, since the thickness of the second flange 27 is greater than the thickness of the first flange 26, the elastic buckling resistance of the H-shaped cross section member 25 is increased, allowing the cross-sectional shape of the H-shaped cross section member 25 to be rationally configured.

[0065] As shown in Figure 28, in building 1A, the corrugated metal roof 35 is attached to the first H-shaped cross section member 15, which is the main beam, via the second H-shaped cross section member 25, which is the purlin. Furthermore, a second H-shaped cross section member 25, which is a furring strip, is fixed to the column 10, and an exterior wall material 55 is attached to this second H-shaped cross section member 25 via a joint member (not shown). The second H-shaped cross section member 25 and the exterior wall material 55 constitute a support structure 57. For example, the exterior wall material 55 has a plurality of siding boards (plate-shaped members) 56. Each siding board 56 is made of cement and extends in the vertical direction. The plurality of siding boards 56 are arranged in the direction of the material axis of the second H-shaped cross section member 25. The plurality of siding boards 56 are positioned on the opposite side of the web 28 with the first flange 26 in between, and are each attached to the first flange 26 via joint members (not shown).

[0066] As shown in Figure 29, in building 1B, the second H-shaped cross section member 25, which is a furring strip, extends vertically, and the exterior wall material 60 is attached to this second H-shaped cross section member 25 via a joint member (not shown). The second H-shaped cross section member 25 and the exterior wall material 60 constitute the support structure 62. For example, the exterior wall material 60 has a plurality of siding boards 61. Each siding board 61 extends along a horizontal plane. The plurality of siding boards 61 are arranged in the direction of the material axis of the second H-shaped cross section member 25. The plurality of siding boards 61 are positioned on the opposite side of the web 28 with the first flange 26 in between, and are each attached to the first flange 26 via joint members.

[0067] Materials such as wood and ALC (Autoclaved Lightweight Aerated Concrete), which are assumed to be used as materials for plate-like members, have a lower Young's modulus than steel plates. However, in return, the thickness of wood and ALC is greater than that of steel plates. For example, while the Young's modulus of wood is about 1 / 20th that of steel, structural plywood is generally 12 mm or thicker. In this case, a rigidity comparable to that of the aforementioned corrugated metal roof can be expected. In other words, the possibility of a drastic decrease in the rigidity of the upper flange restraint section due to a change in material is low, and based on the above analysis results, a sufficient restraining effect on the first flange 26 can be expected for various surface materials. For this reason, plate-like members can be made not only from metal materials, but also from wood-based, ceramic-based, resin-based, and other materials.

[0068] Previous studies have focused on H-shaped cross-sectional members 25 in which the web 28 is attached to the center of the flanges 26 and 27 in the width direction. However, similar effects can be expected for H-shaped cross-sectional members 25 in which the web 28 is not attached to the center of the flanges 26 and 27 in the width direction. Furthermore, a similar effect can be expected even if the first flange 26 or the second flange 27 is bent in a cross-section perpendicular to the material axis direction. However, from a manufacturing and installation perspective, it is preferable that the flanges 26 and 27 are flat.

[0069] The H-shaped cross-section member 25 is not limited to rolled H-shaped steel; it may also be welded H-shaped steel. Furthermore, welded lightweight H-shaped steel (lightweight H-shaped steel) is manufactured from hot-rolled steel strip, cold-rolled steel strip, or plated steel strip by continuous high-frequency resistance welding, or a combination of this and high-frequency induction welding. Since this welded lightweight H-shaped steel is made by dividing a single steel strip with a slitter to form two flanges, it is possible to create a difference in the width of the two flanges without dividing them equally, and thus easily manufacture an H-shaped cross-section with different widths for the upper and lower flanges. For this reason, it is preferable that the H-shaped cross-section member 25 is made of welded lightweight H-shaped steel. The welded lightweight H-shaped steel referred to here includes those specified in JIS G 3353:2011 and those that have received ministerial certification as designated building materials under the Building Standards Act. In this case, the H-shaped cross-sectional member 25 can be made relatively lightweight by using welded lightweight H-shaped steel. The H-shaped cross-section member 25 may be made of ordinary H-shaped steel.

[0070] Although one embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and modifications, combinations, deletions, etc., of the configuration are also included without departing from the spirit of the present invention. [Explanation of Symbols]

[0071] 10 pillars 15 1st H-shaped cross-section member (H-shaped cross-section member) 16,26 First flange 17,27 Second flange 18,28 Web 25 2nd H-shaped cross-section member (H-shaped cross-section member) 35. Corrugated metal roof 36. Corrugated member 37. Base plate (plate-shaped member) 38. First inclined plate (plate-shaped member) 39. Top plate (plate-like component) 40. Second inclined plate (plate-shaped member) 46,47,57,62 Support structure 50 Plate-shaped member 55,60 Exterior wall materials 56,61 Siding boards (plate-shaped members)

Claims

1. First flange and, The second flange and A steel H-shaped cross section member comprising a web that joins the first flange and the second flange to each other, The multiple plate-like members, positioned on the opposite side of the web with the first flange in between and aligned in the material axis direction of the H-shaped cross-section member, are not constructed as a single surface material by concrete, but are each attached to the first flange either directly or via joint members. The width of the second flange is wider than the width of the first flange, and the member has an H-shaped cross-section.

2. First flange and, The second flange and A steel H-shaped cross section member comprising a web that joins the first flange and the second flange to each other, The multiple plate-like members, positioned on the opposite side of the web with the first flange in between and aligned in the material axis direction of the H-shaped cross-section member, are not constructed as a single surface material by concrete, but are each attached to the first flange either directly or via joint members. The second flange is thicker than the first flange, and the H-shaped cross-section member.

3. The H-shaped cross-sectional member according to claim 1 or 2, wherein the plurality of plate-like members constitute a roofing material.

4. The H-shaped cross-sectional member according to claim 1 or 2, wherein the plurality of plate-like members constitute an exterior wall material.

5. An H-shaped cross-sectional member according to any one of claims 1 to 4, wherein it is a welded lightweight H-shaped steel.

6. An H-shaped cross-sectional member according to any one of claims 1 to 5, The plurality of plate-shaped members, A support structure equipped with the following features.

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