Calculation device for cross-sectional performance, calculation method for cross-sectional performance, and calculation program for cross-sectional performance

Abstract

To provide a calculation device for cross-sectional performance capable of calculating the cross-sectional performance of an H-shaped cross sectional member with accuracy at a safer side.SOLUTION: A calculation device 30 for cross-sectional performance of an H-shaped cross-sectional member having a first flange, a second flange, and a web connected to each of the first flange and the second flange is provided with: a coefficient calculation section 32 for calculating each of buckling coefficients of the first flange, the second flange, and the web using elastic buckling stress upon local buckling of the H-shaped sectional member as an integrated one by force acting on the H-shaped sectional member; and a performance calculation section 33 for calculating sectional performance of the H-shaped sectional member using the buckling coefficient.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a cross-sectional performance calculation device, a cross-sectional performance calculation method, and a cross-sectional performance calculation program. [Background technology]

[0002] Conventionally, Non-Patent Document 1 defines a width-thickness ratio limiting formula for plate elements such as H-shaped cross-section members, as shown in formula (0-1). Note that the following discussion is premised on plate elements of H-shaped cross-section members.

[0003]

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[0004] where (b / t) is the width-thickness ratio of one side of the flange of an H-section member in the width direction or the width-thickness ratio of the web of an H-section member, k is the plate buckling coefficient appropriate to the boundary conditions and stress state, E is Young's modulus, and F' is 1 / √3 of the reference strength of the allowable stress of the flange or the reference strength of the allowable stress of the web depending on the width-thickness ratio of the target part and the value of k. The plate buckling coefficient k is, for example, 0.425 for the compression flange and 5.34 for the web.

[0005] Non-Patent Document 1 states that if equation (0-1) is satisfied, the effect of local buckling can be ignored and the cross-sectional performance (section modulus and cross-sectional area of ​​the web) can be calculated assuming that the entire cross-section of the H-shaped cross-section member is effective. The H-shaped section member 10 will be described below with reference to Figure 1. The H-shaped section member 10 has an upper flange 11, a lower flange 12, and a web 13. Furthermore, in Non-Patent Document 1, the ranges R1 and R2 shown by hatching in Figure 1, which exceed the formula (0-1), are invalid, and the effective section modulus and effective cross-sectional area of ​​the web are calculated for the remaining parts, which are used to calculate the yield strength. [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] Edited by the Architectural Institute of Japan, "Allowable Stress Design Criteria for Steel Structures," Maruzen Publishing Co., Ltd., October 2019 [Non-patent document 2] "Guidelines for Buckling Design of Steel Structures," edited by the Architectural Institute of Japan, February 2018 Summary of the Invention [Problem to be solved by the invention]

[0007] However, as mentioned in Non-Patent Document 2, it has been pointed out that H-section members 10 that significantly exceed the value of equation (0-1) are given a risky evaluation. This is because, when calculating the cross-sectional performance (effective section modulus) against bending moments, the range of the ineffective section is based on the width-thickness ratio restriction formula for the individual plate elements, namely the flanges 11 and 12 and the web 13. In other words, when the H-section member 10 locally buckles as a whole, the local buckling stress may be determined by the web 13, and in that case, it is thought that the buckling stress will not rise to the buckling modulus of 0.425 for the flanges 11 and 12 defined by equation (0-1).

[0008] Furthermore, because the calculation of the effective section performance based on Equation (0-1) is specified for each plate element, the mutual restraint effect between the flanges 11, 12 and the web 13 is not taken into account, which can result in an underestimation of the section performance. In particular, the effective section modulus of the web 13 when subjected to bending moment is evaluated using the buckling coefficient of 5.34 for plate elements subjected to pure shear, which is an underestimate due to the different external force conditions. In addition, the effective cross-sectional area of ​​the web 13 that resists shear force is also based on the above buckling coefficient of 5.34, which does not take into account the restraint effect of the flanges 11, 12 at all, resulting in a similar underestimation.

[0009] The present invention has been made in consideration of such problems, and aims to provide a cross-sectional performance calculation device, a cross-sectional performance calculation method, and a cross-sectional performance calculation program that can accurately and safely calculate the cross-sectional performance of H-shaped cross-section members. [Means for solving the problem]

[0010] In order to solve the above problems, the present invention proposes the following means. (1) Aspect 1 of the present invention is a device for calculating the cross-sectional performance of an H-shaped cross-section member having a first flange, a second flange, and webs joined to the first flange and the second flange, the device comprising: a coefficient calculation unit that calculates the buckling coefficients of the first flange, the second flange, and the web using the elastic buckling stress when the H-shaped cross-section member locally buckles as a whole due to an external force acting on the H-shaped cross-section member; and a performance calculation unit that calculates the cross-sectional performance of the H-shaped cross-section member using the buckling coefficients.

[0011] (2) Aspect 2 of the present invention is a method for calculating the cross-sectional performance of an H-shaped cross-section member having a first flange, a second flange, and webs joined to the first flange and the second flange, which includes a coefficient calculation step of calculating the buckling coefficients of the first flange, the second flange, and the web using the elastic buckling stress when the H-shaped cross-section member locally buckles as a whole due to an external force acting on the H-shaped cross-section member, and a performance calculation step of calculating the cross-sectional performance of the H-shaped cross-section member using the buckling coefficients.

[0012] (3) Aspect 3 of the present invention is a cross-sectional performance calculation program for a calculation device that calculates the cross-sectional performance of an H-shaped cross-section member having a first flange, a second flange, and webs joined to the first flange and the second flange, respectively. The cross-sectional performance calculation program causes the calculation device to function as a coefficient calculation unit that calculates the buckling coefficients of the first flange, the second flange, and the web using the elastic buckling stress when the H-shaped cross-section member locally buckles as a whole due to an external force acting on the H-shaped cross-section member, and a performance calculation unit that calculates the cross-sectional performance of the H-shaped cross-section member using the buckling coefficients.

[0013] In these inventions, the coefficient calculation unit (in the coefficient calculation step) calculates the buckling coefficients of the first flange, the second flange, and the web using the elastic buckling stress when the H-section member locally buckles as a whole due to the action of an external force on the H-section member.Then, the performance calculation unit (in the performance calculation step) calculates the cross-sectional performance of the H-section member using the buckling coefficients. Therefore, by using each buckling coefficient, the cross-sectional performance of the H-shaped cross-section member can be calculated accurately and safely.

[0014] (4) Aspect 4 of the present invention may be a cross-sectional performance calculation device as described in (1), in which the external force is a bending moment, and the performance calculation unit calculates the cross-sectional performance by calculating a section modulus. (5) Aspect 5 of the present invention may be a method for calculating cross-sectional performance described in (2), in which the external force is a bending moment, and the performance calculation process calculates the cross-sectional performance by calculating a section modulus. (6) Aspect 6 of the present invention may be a cross-sectional performance calculation program described in (3), in which the external force is a bending moment, and the performance calculation unit calculates the cross-sectional performance by calculating a section modulus.

[0015] In these inventions, when the external force is a bending moment, the performance calculation unit (in the coefficient calculation step) calculates the section modulus, thereby making it possible to calculate the cross-sectional performance.

[0016] (7) Aspect 7 of the present invention may be a cross-sectional performance calculation device as described in (4), in which the H-shaped cross-section member satisfies equation (1-1), and the performance calculation unit calculates the section modulus for the entire cross section perpendicular to the material axis direction of the H-shaped cross-section member in a target flange that is one of the first flange and the second flange. However, b is half the width of the target flange, t f is the thickness of the flange, E is the Young's modulus, F f is the reference strength of the allowable stress of the flange, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k bf is the buckling coefficient of the target flange when the H-shaped section member is subjected to a uniform bending moment and undergoes local buckling.

[0017]

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[0018] (8) Aspect 8 of the present invention may be a method for calculating cross-sectional performance described in (5), in which the H-shaped cross-section member satisfies equation (1-2), and in the performance calculation process, the section modulus is calculated for the entire cross section perpendicular to the material axis direction of the H-shaped cross-section member in the target flange, which is one of the first flange and the second flange. However, b is half the width of the target flange, t f is the thickness of the flange, E is the Young's modulus, F f is the reference strength of the allowable stress of the flange, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k bf is the buckling coefficient of the target flange when the H-shaped section member is subjected to a uniform bending moment and undergoes local buckling.

[0019]

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[0020] (9) A ninth aspect of the present invention may be a cross-sectional performance calculation program described in (6), in which the H-shaped cross-section member satisfies equation (1-3), and the performance calculation unit calculates the section modulus for the entire cross section perpendicular to the material axis direction of the H-shaped cross-section member in a target flange that is one of the first flange and the second flange. However, b is half the width of the target flange, t f is the thickness of the flange, E is the Young's modulus, F f is the reference strength of the allowable stress of the flange, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k bf is the buckling coefficient of the target flange when the H-shaped section member is subjected to a uniform bending moment and undergoes local buckling.

[0021]

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[0022] It should be noted that equation (1-1) is the same as equations (1-2) and (1-3). In these inventions, when the H-shaped cross-section member satisfies formula (1-1), the performance calculation unit (in the performance calculation step) can calculate the section modulus for the entire cross section of the target flange.

[0023] (10) Aspect 10 of the present invention may be a cross-sectional performance calculation device as described in (4), in which the H-shaped cross-section member satisfies equation (2-1), and the performance calculation unit calculates the section modulus for the entire cross section in the web perpendicular to the material axis direction of the H-shaped cross-section member. where d is the inner dimension of the H-shaped cross-section member, t w is the thickness of the web, E is Young's modulus, F w is the reference strength of the allowable stress of the web, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k bw is the buckling coefficient of the web when the H-section member is subjected to a uniform bending moment and undergoes local buckling.

[0024]

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[0025] (11) Aspect 11 of the present invention may be a method for calculating cross-sectional properties as described in (5), in which the H-shaped cross-section member satisfies equation (2-2), and in the performance calculation step, the section modulus is calculated for the entire cross section in the web that is perpendicular to the material axis direction of the H-shaped cross-section member. where d is the inner dimension of the H-shaped cross-section member, t w is the thickness of the web, E is Young's modulus, F w is the reference strength of the allowable stress of the web, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k bw is the buckling coefficient of the web when the H-section member is subjected to a uniform bending moment and undergoes local buckling.

[0026]

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[0027] (12) Aspect 12 of the present invention may be a cross-sectional performance calculation program described in (6), in which the H-shaped cross-section member satisfies equation (2-3), and the performance calculation unit calculates the section modulus for the entire cross section in the web perpendicular to the material axis direction of the H-shaped cross-section member. where d is the inner dimension of the H-shaped cross-section member, t w is the thickness of the web, E is Young's modulus, F w is the reference strength of the allowable stress of the web, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k bw is the buckling coefficient of the web when the H-section member is subjected to a uniform bending moment and undergoes local buckling.

[0028]

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[0029] It should be noted that equation (2-1) is the same as equations (2-2) and (2-3). In these inventions, when the H-section member satisfies formula (2-1), the performance calculation unit (in the performance calculation step) can calculate the section modulus for the entire cross section of the web.

[0030] (13) Aspect 13 of the present invention may be a cross-sectional performance calculation device as described in (4), in which the H-shaped cross-section member satisfies equation (3-1), and the performance calculation unit calculates the section modulus for an effective flange width calculated by multiplying the right-hand side of equation (3-1) by the thickness of the target flange from a cross-section perpendicular to the material axis direction of the H-shaped cross-section member at a target flange, which is one of the first flange and the second flange, excluding the range exceeding the right-hand side of equation (3-1). However, b is half the width of the target flange, t f is the thickness of the flange, E is the Young's modulus, F f is the reference strength of the allowable stress of the flange, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k bf is the buckling coefficient of the target flange when the H-shaped section member is subjected to a uniform bending moment and undergoes local buckling.

[0031]

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[0032] (14) Aspect 14 of the present invention may be a method for calculating cross-sectional performance described in (5), in which the H-shaped cross-section member satisfies equation (3-2), and in the performance calculation step, the section modulus is calculated for an effective flange width calculated by multiplying the right-hand side of equation (3-2) by the thickness of the target flange from a cross-section perpendicular to the material axis direction of the H-shaped cross-section member at a target flange, which is one of the first flange and the second flange, excluding the range exceeding the right-hand side of equation (3-2). However, b is half the width of the target flange, t f is the thickness of the flange, E is the Young's modulus, F f is the reference strength of the allowable stress of the flange, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k bfis the buckling coefficient of the target flange when the H-shaped section member is subjected to a uniform bending moment and undergoes local buckling.

[0033]

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[0034] (15) Aspect 15 of the present invention may be a cross-sectional performance calculation program described in (6), in which the H-shaped cross-section member satisfies equation (3-3), and the performance calculation unit calculates the section modulus for an effective flange width calculated by multiplying the right-hand side of equation (3-2) by the thickness of the target flange from a cross-section perpendicular to the material axis direction of the H-shaped cross-section member at a target flange, which is one of the first flange and the second flange, excluding the range exceeding the right-hand side of equation (3-3). However, b is half the width of the target flange, t f is the thickness of the flange, E is the Young's modulus, F f is the reference strength of the allowable stress of the flange, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k bf is the buckling coefficient of the target flange when the H-shaped section member is subjected to a uniform bending moment and undergoes local buckling.

[0035]

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[0036] It should be noted that equation (3-1) is the same as equations (3-2) and (3-3). In these inventions, when an H-shaped cross-section member satisfies equation (3-1) and the H-shaped cross-section member has an invalid cross-section, the performance calculation unit (in the performance calculation process) can calculate the section modulus for the cross-section of the target flange excluding the invalid cross-section.

[0037] (16) Aspect 16 of the present invention may be a cross-sectional performance calculation device as described in (4), in which the H-shaped cross-section member satisfies equation (4-1), and the performance calculation unit calculates the section modulus excluding a cross-section perpendicular to the material axis direction of the H-shaped cross-section member at the web, which is within the range of the invalid web height d' obtained by equation (5-1) from the centroid of the web in the direction in which the first flange and the second flange face each other. where d is the inner dimension of the H-shaped cross-section member, t w is the thickness of the web, E is Young's modulus, F w is the reference strength of the allowable stress of the web, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k bw is the buckling coefficient of the web when the H-section member is subjected to a uniform bending moment and undergoes local buckling.

[0038]

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[0039] (17) Aspect 17 of the present invention may be a method for calculating cross-sectional performance described in (5), in which the H-shaped cross-section member satisfies equation (4-2), and in the performance calculation step, the section modulus is calculated excluding a cross-section at the web that is perpendicular to the material axis direction of the H-shaped cross-section member and that falls within the range of the invalid web height d' obtained by equation (5-2) in the direction in which the first flange and the second flange face each other from the centroid of the web. where d is the inner dimension of the H-shaped cross-section member, t w is the thickness of the web, E is Young's modulus, F w is the reference strength of the allowable stress of the web, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k bw is the buckling coefficient of the web when the H-section member is subjected to a uniform bending moment and undergoes local buckling.

[0040]

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[0041] (18) Aspect 18 of the present invention may be a cross-sectional performance calculation program described in (6), in which the H-shaped cross-section member satisfies equation (4-3), and the performance calculation unit calculates the section modulus excluding a cross-section perpendicular to the material axis direction of the H-shaped cross-section member at the web, which is within the range of the invalid web height d' obtained by equation (5-3) from the centroid of the web in the direction in which the first flange and the second flange face each other. where d is the inner dimension of the H-shaped cross-section member, t w is the thickness of the web, E is Young's modulus, F w is the reference strength of the allowable stress of the web, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k bw is the buckling coefficient of the web when the H-section member is subjected to a uniform bending moment and undergoes local buckling.

[0042]

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[0043] It should be noted that equation (4-1) is the same as equations (4-2) and (4-3), and equation (5-1) is the same as equations (5-2) and (5-3). In these inventions, when an H-section member satisfies equation (4-1) and has an invalid section based on the invalid web height d' obtained by equation (5-1), the performance calculation unit (in the performance calculation process) can calculate the section modulus for the web excluding the invalid section.

[0044] (19) Aspect 19 of the present invention may be a cross-sectional performance calculation device described in (1), in which the external force is a shear force and the performance calculation unit calculates the cross-sectional performance by calculating a cross-sectional area. (20) Aspect 20 of the present invention may be a method for calculating cross-sectional performance described in (2), in which the external force is a shear force, and the performance calculation process calculates the cross-sectional performance by calculating a cross-sectional area. (21) Aspect 21 of the present invention may be a cross-sectional performance calculation program described in (3), in which the external force is a shear force, and the performance calculation unit calculates the cross-sectional performance by calculating a cross-sectional area.

[0045] In these inventions, when the external force is a shear force, the performance calculation unit (in the performance calculation step) can calculate the cross-sectional area to thereby calculate the cross-sectional performance.

[0046] (22) Aspect 22 of the present invention may be a cross-sectional performance calculation device described in (19), in which the H-shaped cross-section member satisfies equation (6-1), and the performance calculation unit calculates the entire cross-section in the web perpendicular to the material axis direction of the H-shaped cross-section member as the cross-sectional area. where d is the inner dimension of the H-shaped cross-section member, t w is the thickness of the web, E is Young's modulus, F w is the reference strength of the allowable stress of the web, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k sw is the buckling coefficient of the web when the H-section member is subjected to pure shear and buckles in shear.

[0047]

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[0048] (23) Aspect 23 of the present invention may be a method for calculating cross-sectional performance described in (20), in which the H-shaped cross-section member satisfies equation (6-2), and in the performance calculation process, the entire cross-section in the web perpendicular to the material axis direction of the H-shaped cross-section member is calculated as the cross-sectional area. where d is the inner dimension of the H-shaped cross-section member, t w is the thickness of the web, E is Young's modulus, F w is the reference strength of the allowable stress of the web, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k sw is the buckling coefficient of the web when the H-section member is subjected to pure shear and buckles in shear.

[0049]

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[0050] (24) Aspect 24 of the present invention may be a cross-sectional performance calculation program described in (21), in which the H-shaped cross-section member satisfies equation (6-3), and the performance calculation unit calculates the entire cross-section in the web perpendicular to the material axis direction of the H-shaped cross-section member as the cross-sectional area. where d is the inner dimension of the H-shaped cross-section member, t w is the thickness of the web, E is Young's modulus, F w is the reference strength of the allowable stress of the web, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k sw is the buckling coefficient of the web when the H-section member is subjected to pure shear and buckles in shear.

[0051]

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[0052] It should be noted that equation (6-1) is the same as equations (6-2) and (6-3). In these inventions, when the H-section member satisfies formula (6-1), the performance calculation unit (in the performance calculation step) can calculate the cross-sectional area for the entire cross section of the web.

[0053] (25) Aspect 25 of the present invention may be a cross-sectional performance calculation device as described in (19), in which the H-shaped cross-section member satisfies equation (7-1), and the performance calculation unit calculates the cross-sectional area excluding a cross-section perpendicular to the material axis direction of the H-shaped cross-section member at the web, which is within the range of the invalid web height d' obtained by equation (8-1) from the centroid of the web in the direction in which the first flange and the second flange face each other. where d is the inner dimension of the H-shaped cross-section member, t w is the thickness of the web, E is Young's modulus, F w is the reference strength of the allowable stress of the web, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k swis the buckling coefficient of the web when the H-section member is subjected to pure shear and buckles in shear.

[0054]

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[0055] (26) Aspect 26 of the present invention may be a method for calculating cross-sectional performance described in (20), in which the H-shaped cross-section member satisfies equation (7-2), and in the performance calculation step, the cross-sectional area is calculated excluding a cross-section at the web that is perpendicular to the material axis direction of the H-shaped cross-section member and that falls within the range of the effective web height d' obtained by equation (8-2) from the centroid of the web in the direction in which the first flange and the second flange face each other. where d is the inner dimension of the H-shaped cross-section member, t w is the thickness of the web, E is Young's modulus, F w is the reference strength of the allowable stress of the web, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k sw is the buckling coefficient of the web when the H-section member is subjected to pure shear and buckles in shear.

[0056]

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[0057] (27) Aspect 27 of the present invention may be a cross-sectional performance calculation program described in (21), in which the H-shaped cross-section member satisfies equation (7-3), and the performance calculation unit calculates the cross-sectional area excluding a cross-section perpendicular to the material axis direction of the H-shaped cross-section member at the web, which is within the range of the invalid web height d' obtained by equation (8-3) from the centroid of the web in the direction in which the first flange and the second flange face each other. where d is the inner dimension of the H-shaped cross-section member, t w is the thickness of the web, E is Young's modulus, F w is the reference strength of the allowable stress of the web, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k swis the buckling coefficient of the web when the H-section member is subjected to pure shear and buckles in shear.

[0058]

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[0059] It should be noted that equation (7-1) is the same as equations (7-2) and (7-3), and equation (8-1) is the same as equations (8-2) and (8-3). In these inventions, when an H-shaped cross-section member satisfies equation (7-1) and has an invalid cross-section based on the invalid web height d' obtained by equation (8-1), the performance calculation unit (in the performance calculation process) can calculate the cross-sectional area of ​​the web excluding the invalid cross-section. [Effects of the Invention]

[0060] The cross-sectional performance calculation device, cross-sectional performance calculation method, and cross-sectional performance calculation program of the present invention can calculate the cross-sectional performance of H-shaped cross-section members accurately and safely. [Brief explanation of the drawings]

[0061] [Figure 1] FIG. 2 is a front view of the H-shaped cross-section member. [Figure 2] 1 is a flowchart illustrating a method for calculating cross-sectional performance according to an embodiment of the present invention. [Figure 3] FIG. 10 is a diagram showing an outline of an experimental device using the same H-shaped cross-section member. [Figure 4] This figure shows the change in bending moment M acting on the H-shaped cross-section member between loading points in sample No. 1 relative to the rotation angle θ of the H-shaped cross-section member at the loading points. [Figure 5] FIG. 10 is a graph showing the change in shear force P acting between the loading point and the support point relative to the downward displacement δ at the loading point in sample No. 2. [Figure 6]This figure shows the change in bending moment M acting on the H-shaped cross-section member between loading points in sample No. 3 relative to the rotation angle θ of the H-shaped cross-section member at the loading points. [Figure 7] FIG. 10 is a graph showing the change in shear force P acting between the loading point and the support point relative to the downward displacement δ at the loading point in sample No. 4. [Figure 8] 1 is a diagram showing an overview of a cross-sectional performance calculation device according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0062] Below, one embodiment of the cross-sectional performance calculation device (hereinafter simply referred to as the calculation device), cross-sectional performance calculation method (hereinafter simply referred to as the calculation method), and cross-sectional performance calculation program (hereinafter simply referred to as the calculation program) related to the present invention will be described with reference to Figures 1 to 8. Below, we will first explain the H-shaped cross-section member that is the subject of calculation using the calculation device, calculation method, and calculation program.

[0063] [1. Structure of H-shaped cross-section members] 1, for example, an H-shaped section member 10 extends in a material axis direction Z along a horizontal plane. The H-shaped section member 10 has an upper flange (first flange) 11, a lower flange (second flange) 12, and a web 13. The upper flange 11, the lower flange 12, and the web 13 are each formed into a flat plate shape using a steel plate. The upper flange 11, the lower flange 12, and the web 13 are each a plate element. The upper flange 11 and the lower flange 12 face each other in the vertical direction X. That is, the vertical direction X is the direction in which the upper flange 11 and the lower flange 12 face each other. Here, the direction perpendicular to the material axis direction Z and the up-down direction X is defined as the width direction Y.

[0064] The upper flange 11 is disposed above the lower flange 12 . The web 13 is disposed between the upper flange 11 and the lower flange 12. The web 13 is joined to the middle portion of the upper flange 11 in the width direction Y and the middle portion of the lower flange 12 in the width direction Y, respectively. The direction in which the H-section member 10 extends and the direction in which the flanges 11, 12 face each other are not limited to these. The H-section member 10 may be an H-beam. In this case, the H-section member 10 may be a rolled H-beam or a welded H-beam.

[0065] [2. Specifications for H-section members] Here, the specifications of the H-shaped cross-section member 10 will be defined. The thickness of each of the upper flange 11 and the lower flange 12 is t f The thickness of the web 13 is defined as t (mm). w The inner depth of the H-shaped cross-section member 10 (web 13) is defined as d (mm). Half the width (length in the width direction Y) of each of the upper flange 11 and the lower flange 12 is defined as b (mm). The Young's modulus of the H-shaped cross-section member 10 is E (N / mm 2 The standard strength of the allowable stress of each of the upper flange 11 and the lower flange 12 is set as F f (N / mm 2 The reference strength of the allowable stress of the web 13 is defined as F w (N / mm 2 ) is stipulated. The thickness of the upper flange 11 and the thickness of the lower flange 12 may be different from each other. The half length of the width of the upper flange 11 and the half length of the width of the lower flange 12 may be different from each other.

[0066] The buckling coefficients of the upper flange 11 and the lower flange 12 when the H-shaped section member 10 is subjected to a uniform bending moment and undergoes local buckling are defined as k bf The buckling coefficient of the web 13 when the H-section member 10 is subjected to a uniform bending moment and undergoes local buckling is defined as k bw The buckling coefficient of the web 13 when the H-section member 10 is subjected to a pure shear force and undergoes shear buckling is defined as ksw (-) is specified. The coefficient determined by the magnitude of the shape imperfection and residual stress of the H-section member 10 is defined as α(-).

[0067] As the geometric imperfections and residual stresses of the H-section member 10 increase, the coefficient α decreases. It is generally believed that due to the effects of geometric imperfections and residual stresses, linear elasticity cannot be maintained and the material enters the nonlinear region at a stress of 0.6 times the yield strength. Based on this idea, the coefficient α is 0.818.

[0068] 3. Calculation method of this embodiment In this embodiment, we considered changing the calculation method depending on whether the external force acting on the H-section member 10 is a bending moment or a shear force (hereinafter referred to as the external force type), and whether or not the H-section member 10 has an ineffective cross section. The bending moment here refers to the bending moment around the strong axis of the H-section member 10 (axis L6 along the width direction Y shown in Figure 1). As shown in FIG. 2, the calculation methods S1, S2, S3, S4, S6, and S7 of this embodiment include a coefficient calculation step S11 and performance calculation steps S21, S22, S23, S24, S26, and S27.

[0069] In the coefficient calculation process S11, the buckling coefficients of the upper flange 11, the lower flange 12, and the web 13 are calculated using the elastic buckling stress when the H-shaped cross-section member 10 buckles locally as a whole due to an external force acting on the H-shaped cross-section member 10. These buckling coefficients can be calculated, for example, as follows (1) to (3): (1) Calculation is based on the buckling stress estimation method disclosed in Japanese Patent No. 7211282 and Japanese Patent No. 7211287. (2) Approximation formulas and regression formulas based on the results of structural experiments and FEM analysis are used. (3) The buckling stress at the time of local buckling is calculated by FEM buckling eigenvalue analysis, and this buckling stress is converted into the buckling coefficient.

[0070] In addition, when calculating the elastic buckling stress, it is desirable that the length (member length) of the H-shaped cross-section member 10 be a length that can be considered infinite in order to evaluate the buckling restraint effect of the end of the H-shaped cross-section member 10 on the safe side.

[0071] In the performance calculation steps S21, S22, S23, and S24 described below when the external force type is a bending moment, the cross-sectional performance is calculated by calculating the section modulus. More specifically, in the performance calculation steps S21, S22, S23, and S24, the cross-sectional performance of the H-section member 10 is calculated using each buckling coefficient. In the following description, the target flange that is the target of calculation by calculation methods S1, S3, and S4, which is one of the top flange 11 and the bottom flange 12, is assumed to be the top flange 11. Note that the target flange may also be the bottom flange 12.

[0072] [3.1. When the external force type is a bending moment and the flange has no ineffective cross section] In the calculation method S1, when the H-shaped cross section member 10 satisfies the formula (11), the section modulus is calculated for all cross sections of the upper flange 11 perpendicular to the material axis direction Z in the performance calculation step S21.

[0073]

number

[0074] When calculating the section modulus, the entire cross section perpendicular to the material axis direction Z in the upper flange 11 is considered valid. Then, for example, the calculated section modulus of the upper flange 11 is z f1 (mm 3 The yield strength of the steel material forming the upper flange 11 is defined as σ yf1 (N / mm 2 The section modulus of the bottom flange 12 is defined as z f2 (mm 3 The yield strength of the steel material forming the bottom flange 12 is defined as σ yf2 (N / mm 2 The section modulus of the web 13 is defined as z w (mm3 The yield strength of the steel material forming the web 13 is defined as σ yw (N / mm 2 ) is stipulated. At this time, the bending strength M of the H-shaped cross-section member 10, which is the cross-sectional performance, is calculated by the formula (11-1). e Calculate the value (N·mm). M e =z f1 σ yf1 +z f2 σ yf2 +z w σ yw (11-1)

[0075] [3.2. When the external force type is bending moment and the web has no ineffective cross section] In the calculation method S2, when the H-section member 10 satisfies the formula (12), the section modulus is calculated for all cross sections perpendicular to the material axis direction Z in the web 13 in the performance calculation step S22.

[0076]

number

[0077] In the following sections [3.3] and [3.4], the bending strength M of the H-shaped cross-section member 10 is calculated from the section modulus. u The method for finding is the same as in [3.1].

[0078] [3.3. When the external force type is a bending moment and the flange has an ineffective cross section] In the calculation method S3, when the H-shaped cross section member 10 satisfies the formula (13), in the performance calculation step S23, the thickness t of the upper flange 11 is added to the right side of the formula (13) on the cross section perpendicular to the material axis direction Z of the upper flange 11, excluding the range exceeding the right side of the formula (13). w The section modulus is calculated for the effective flange width calculated by multiplying the above. When calculating the section modulus, the cross section of the upper flange 11 that has been removed is invalid.

[0079]

number

[0080] That is, for example, the range R1 for the upper flange 11 in FIG. 1 is invalid. For example, based on the right-hand side of equation (13), {α√(k bf E / F f )×t w The value calculated from the formula} is the effective flange width. The section modulus of the flanges 11, 12 of the H-section member 10 is calculated using this effective flange width by a known method.

[0081] [3.4. When the external force type is bending moment and there is an ineffective section in the web] In calculation method S4, if the H-section member 10 satisfies equation (14), the section modulus is calculated in performance calculation step S24, excluding the cross section perpendicular to the material axis direction Z of the web 13, which is within the range of the invalid web height d' obtained by equation (15) in the vertical direction X from the centroid of the web 13.

[0082]

number

[0083] That is, the range R2 for the web 13 in FIG. 1 is invalidated.

[0084] Next, a case where the type of external force is a shear force will be described. In the performance calculation steps S26 and S27 when the external force type is a shear force, which will be described below, the cross-sectional area is calculated to calculate the cross-sectional performance.

[0085] [3.5. When the external force type is shear force and there is no dead section in the web] In calculation method S6, if the H-section member 10 satisfies equation (16), in performance calculation step S26, the entire cross section of the web 13 perpendicular to the material axis direction Z is calculated as the cross-sectional area. When calculating the cross-sectional area, the entire cross section of the web 13 perpendicular to the material axis direction Z is considered valid.

[0086]

number

[0087] Then, for example, the calculated cross-sectional area of ​​the web 13 is expressed as A we (mm 2 ) is stipulated. At this time, the shear strength Q of the H-shaped cross-section member 10, which is the cross-sectional performance, is calculated using equation (16-1). e Find (N). Q e =A we (σ yw / √3) ··(16-1)

[0088] [3.6. When the external force type is shear force and there is an ineffective section in the web] In calculation method S7, if the H-section member 10 satisfies equation (17), the performance calculation step S27 calculates the cross-sectional area excluding the cross section perpendicular to the material axis direction Z of the web 13, which is within the range of the invalid web height d' obtained by equation (18) in the vertical direction X from the centroid of the web 13.

[0089]

number

[0090] That is, for example, the range R2 for the web 13 in FIG. 1 is invalidated. In addition, the shear strength Q of the H-shaped cross-section member 10 is calculated from the cross-sectional area of ​​the web 13 calculated in [3.6]. e The method for finding is the same as in [3.5].

[0091] [4. Conventional calculation method] On the other hand, for example, the conventional calculation method is a method of calculating the section modulus of the upper flange 11, lower flange 12 and web 13 of the H-shaped cross-section member 10 or the cross-sectional area of ​​the web 13, as described in paragraphs

[0004] and

[0005] in the background art of this specification.

[0092] [5. Experimental study of the calculation method] Using the experimental device 100 shown in FIG. 3, a structural experiment was carried out by four-point bending of an H-shaped cross-section member 10 as a test specimen. The experimental device 100 includes two support parts 101, a load part 102, and two load-carrying parts 103. The two support parts 101 are arranged on the support surface F1 along a horizontal plane with a gap between them. The two support parts 101 support the H-shaped section member 10 from below the H-shaped section member 10. The part of each support part 101 that is in contact with the H-shaped section member 10 is the fulcrum 101a.

[0093] The load portion 102 applies a downward load F3. The two loading sections 103 are attached to the load section 102 and are arranged at a distance from each other in the direction in which the two support sections 101 are aligned. The two loading sections 103 are in contact with the H-shaped section member 10 from above the H-shaped section member 10. The part of each loading section 103 that is in contact with the H-shaped section member 10 is the loading point 103a. In the material axis direction Z in which the H-shaped section member 10 extends, the two loading points 103a are disposed between the two supporting points 101a.

[0094] A comparison was made between the conventional calculation method and the calculation method of this embodiment for an H-shaped section member 10 whose width-thickness ratio greatly exceeds the limit value of the equation (0-1). The cross-sectional shape of the H-shaped section member 10 used in the experiment is shown in Table 1.

[0095] [Table 1]

[0096] For example, the cross-sectional shapes of the H-section members 10 of Samples No. 1 and No. 2 are H-450 x 125 x 3.6 x 6.0. In Sample No. 1, appropriate reinforcing members were provided on the H-section member 10 at the positions of the fulcrum 101a and the loading point 103a so that the H-section member 10 buckles between the two loading points 103a in the material axis direction Z. In Sample No. 2, appropriate reinforcing members were provided on the H-section member 10 at the positions of the fulcrum 101a and the loading point 103a so that the H-section member 10 buckles between the fulcrum 101a and the loading point 103a in the material axis direction Z. Samples No. 1 and No. 3 are samples for verifying the validity of the calculation method when the external force is a bending moment. Samples No. 2 and No. 4 are samples for verifying the validity of the calculation method when the external force is a shear force.

[0097] For samples No. 1 to No. 4, the lower limit of the yield strength standard was set at 440 N / mm, which is the stricter side of the elastic range for local buckling. 2 The H-shaped cross section member 10 is manufactured using high strength material. Samples No. 1 to No. 4 are cases where there is an ineffective cross section.

[0098] Figures 4 to 7 show the load-deformation relationships obtained from structural experiments. For example, Figure 4 shows the results for sample No. 1. In Figure 4, the horizontal axis represents the rotation angle θ of the H-shaped section member 10 at the loading points 103a, and the vertical axis represents the bending moment M acting on the H-shaped section member 10 between the loading points 103a. In all of FIGS. 4 to 7, the results obtained by the conventional calculation method are indicated by a dotted line L1, and the results obtained by the calculation method of this embodiment are indicated by a solid line L2. Lines L1 and L2 show the effective section performance (section modulus or cross-sectional area of ​​web 13) of the conventional and present calculation methods converted into proof stress by multiplying it by the yield strength of the H-section member 10. The coefficient α was calculated at 0.818.

[0099] Conventional calculation methods sometimes overestimate and sometimes underestimate the maximum strength of the H-section member 10. That is, in Figures 4 to 7, the bending moment M and shear force P indicated by line L1 are sometimes larger than the maximum values ​​of bending moment M and shear force P in the curves showing the load-deformation relationship, and sometimes smaller. In contrast to this, the calculation method of this embodiment makes it possible to accurately evaluate the maximum strength of the H-shaped cross section member 10 while remaining on the safe side. That is, in Figures 4 to 7, the bending moment M and shear force P indicated by line L2 are always smaller than the maximum values ​​of bending moment M and shear force P in the curves showing the load-deformation relationship, and are closer to the maximum values ​​of bending moment M and shear force P than line L1.

[0100] [6. Calculation device, calculation method, and calculation program] Next, the calculation device, calculation method, and calculation program of this embodiment will be described.

[0101] 8 shows the calculation device 30 of this embodiment. The calculation device 30 calculates the cross-sectional properties of the H-section member 10. The calculation device 30 is a computer and includes a CPU (Central Processing Unit) 31, a main memory device 35, an auxiliary memory device 40, an input / output interface (IO·I / F) 45, and a recording / playback device 50. The CPU 31, the main memory device 35, the auxiliary memory device 40, the input / output interface 45, and the recording / playback device 50 are connected to one another by a bus 55. The main storage device 35 is a RAM (Random Access Memory) or the like that serves as a work area for the CPU 31 or the like. The input / output interface 45 is connected to an input device 46 such as a keyboard and a mouse, and a display device 47 . A recording / playback device 50 records and plays back data on a recording medium 51 such as a USB (Universal Serial Bus) memory.

[0102] The auxiliary storage device 40 is a hard disk drive device or the like that stores various data, programs, etc. The auxiliary storage device 40 stores a calculation program 41 for causing the computer to function as the calculation device 30, various programs such as an OS program, etc. The various programs including the calculation program 41 are loaded into the auxiliary storage device 40 from a recording medium 51 via a recording / playback device 50. The calculation program 41, etc. are stored in the recording medium 51. These programs may be loaded into the auxiliary storage device 40 from a disk-type recording medium such as a CD or DVD, or from an external device via a communication device (not shown).

[0103] The CPU 31 executes various types of calculation processing and functionally includes a coefficient calculation unit 32 and a performance calculation unit 33. The coefficient calculation unit 32 calculates the buckling coefficients of each of the upper flange 11, the lower flange 12, and the web 13 using the elastic buckling stress when the H-shaped cross-section member 10 locally buckles as a whole due to an external force acting on the H-shaped cross-section member 10.

[0104] The performance calculation unit 33 calculates the cross-sectional performance by calculating the section modulus. More specifically, the performance calculation unit 33 calculates the cross-sectional performance of the H-section member 10 using each buckling coefficient.

[0105] When the type of external force is a bending moment, there is no ineffective section in the upper flange 11, and the H-shaped cross-section member 10 satisfies equation (11), the performance calculation unit 33 calculates the section modulus for all sections in the upper flange 11 perpendicular to the material axis direction Z. When the type of external force is a bending moment, there is no ineffective section in the web 13, and the H-shaped cross-section member 10 satisfies equation (12), the performance calculation unit 33 calculates the section modulus for all cross sections in the web 13 perpendicular to the material axis direction Z.

[0106] When the external force type is a bending moment, the upper flange 11 has an ineffective section, and the H-shaped cross-section member 10 satisfies equation (13), the performance calculation unit 33 calculates the thickness t of the upper flange 11 on the right side of equation (13) from the cross section perpendicular to the material axis direction Z of the upper flange 11, excluding the range exceeding the right side of equation (13). w Calculate the section modulus for the effective flange width calculated by multiplying by . When the type of external force is a bending moment, the web 13 has an ineffective section, and the H-section member 10 satisfies equation (14), the performance calculation unit 33 calculates the section modulus excluding the section that is perpendicular to the material axis direction Z in the web 13 and falls within the range of the ineffective web height d' obtained by equation (15) in the vertical direction X from the centroid of the web 13.

[0107] On the other hand, when the external force is a shear force, the performance calculation unit 33 calculates the cross-sectional performance by calculating the cross-sectional area as follows. If the web 13 has no ineffective cross section and the H-shaped cross section member 10 satisfies equation (16), the performance calculation unit 33 calculates the entire cross section of the web 13 perpendicular to the material axis direction Z as the cross-sectional area. When the web 13 has an ineffective section and the H-section member 10 satisfies equation (17), the performance calculation unit 33 calculates the cross-sectional area excluding the section that is perpendicular to the material axis direction Z in the web 13 and is within the range of the ineffective web height d' obtained by equation (18) in the vertical direction X from the centroid of the web 13.

[0108] The coefficient calculation unit 32 and performance calculation unit 33, which are functional components of the CPU 31, function when the CPU 31 executes a calculation program 41 and the like stored in the auxiliary storage device 40. The calculation program 41 is a program for the calculation device 30 that calculates the cross-sectional performance of the H-shaped cross-section member 10. The calculation program 41 causes the calculation device 30 to function as the coefficient calculation unit 32 and the performance calculation unit 33.

[0109] 7. Effects of this embodiment As described above, in the calculation device 30, calculation methods S1, S2, S3, S4, S6, and S7, and calculation program 41 of this embodiment, the coefficient calculation unit 32 (in coefficient calculation step S11) calculates the buckling coefficients of the upper flange 11, the lower flange 12, and the web 13, respectively, using the elastic buckling stress when the H-section member 10 locally buckles as a whole due to the application of an external force to the H-section member 10. Then, the performance calculation unit 33 (in performance calculation steps S21, S22, S23, S24, S26, and S27) calculates the cross-sectional performance of the H-section member 10 using the buckling coefficients. Therefore, by using each buckling coefficient, the cross-sectional performance of the H-shaped section member 10 can be calculated accurately and safely.

[0110] When the type of external force is bending moment, the performance calculation unit 33 (in performance calculation steps S21, S22, S23, and S24) can calculate the section performance by calculating the section modulus. When the type of external force is a bending moment, the upper flange 11 has no ineffective cross section, and the H-shaped cross section member 10 satisfies equation (11), the performance calculation unit 33 can calculate the section modulus for the entire cross section of the upper flange 11 (in the performance calculation step S21).

[0111] When the type of external force is a bending moment, the web 13 has no ineffective cross section, and the H-shaped cross-section member 10 satisfies equation (12), the performance calculation unit 33 can calculate the section modulus for the entire cross section of the web 13 (in the performance calculation step S22). When the type of external force is a bending moment, the upper flange 11 has an ineffective section, and the H-shaped cross-section member 10 satisfies equation (13), the performance calculation unit 33 (in the performance calculation step S23) can calculate the section coefficient for the section of the upper flange 11 including the ineffective section.

[0112] When the type of external force is a bending moment, the web 13 has an ineffective cross section, and the H-shaped cross-section member 10 satisfies equation (14), the performance calculation unit 33 (in the performance calculation step S24) can calculate the section modulus for the web 13 including the ineffective cross section. On the other hand, when the external force type is shear force, the performance calculation unit 33 (in the performance calculation steps S26 and S27) can calculate the cross-sectional performance by calculating the cross-sectional area.

[0113] If the type of external force is shear force, there is no ineffective cross section in the web 13, and the H-shaped cross section member 10 satisfies equation (16), the performance calculation unit 33 can calculate the cross-sectional area for the entire cross section of the web 13 (in the performance calculation step S26). When the type of external force is a shear force, the web 13 has an ineffective cross section, and the H-shaped cross-section member 10 satisfies equation (17), the performance calculation unit 33 (in the performance calculation step S27) can calculate the cross-sectional area of ​​the web 13 including the ineffective cross section.

[0114] 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 configuration changes, combinations, deletions, etc. are also included within the scope that does not deviate from the gist of the present invention. [Explanation of symbols]

[0115] 10 H-shaped cross-section member 11 Upper flange (first flange) 12 Lower flange (second flange) 13. Web 30 Calculation device (cross-sectional performance calculation device) 32 Coefficient Calculation Section 33 Performance Calculation Department 41 Calculation program (cross-sectional performance calculation program) S1, S2, S3, S4, S6, S7 Calculation Method (Calculation Method of Sectional Performance) S11 Coefficient calculation process S21, S22, S23, S24, S26, S27 Performance calculation process

Claims

1. A device for calculating cross-sectional properties of an H-shaped section member having a first flange, a second flange, and a web joined to the first flange and the second flange, a coefficient calculation unit that calculates a buckling coefficient for each of the first flange, the second flange, and the web using an elastic buckling stress when the H-shaped cross-section member locally buckles as a whole due to an external force acting on the H-shaped cross-section member; a performance calculation unit that calculates the cross-sectional performance of the H-shaped cross-section member using the buckling coefficient; A cross-sectional performance calculation device comprising:

2. the external force is a bending moment, The cross-sectional performance calculation device according to claim 1 , wherein the performance calculation unit calculates the cross-sectional performance by calculating a section modulus.

3. The H-shaped cross-section member satisfies formula (1), 3. The cross-sectional performance calculation device according to claim 2, wherein the performance calculation unit calculates the section modulus for the entire cross section perpendicular to the material axis direction of the H-shaped cross-section member in a target flange, which is one of the first flange and the second flange. where b is half the width of the target flange, t ｆ is the thickness of the target flange, E is Young's modulus, F ｆ is the reference strength of the allowable stress of the target flange, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k ｂｆ is the buckling coefficient of the target flange when the H-shaped section member is subjected to a uniform bending moment and undergoes local buckling. [Equation 1]

4. The H-shaped cross-section member satisfies formula (2), The cross-sectional performance calculation device according to claim 2 , wherein the performance calculation unit calculates the section modulus for all cross sections in the web that are perpendicular to the material axis direction of the H-shaped cross-section member. where d is the inner diameter of the H-shaped cross section member, t ｗ is the thickness of the web, E is Young's modulus, F ｗ is the reference strength of the allowable stress of the web, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k ｂｗ is the buckling coefficient of the web when the H-section member is subjected to a uniform bending moment and undergoes local buckling. [Equation 2]

5. The H-shaped cross-section member satisfies formula (3), 3. The cross-sectional performance calculation device according to claim 2, wherein the performance calculation unit calculates the section modulus for an effective flange width calculated by multiplying the right-hand side of equation (3) by the thickness of the target flange from a cross-section perpendicular to the material axis direction of the H-shaped cross-section member in the target flange, which is one of the first flange and the second flange, excluding the range exceeding the right-hand side of equation (3). where b is half the width of the target flange, t ｆ is the thickness of the target flange, E is Young's modulus, F ｆ is the reference strength of the allowable stress of the target flange, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k ｂｆ is the buckling coefficient of the target flange when the H-shaped section member is subjected to a uniform bending moment and undergoes local buckling. [Equation 3]

6. The H-shaped cross-section member satisfies formula (4), 3. The cross-sectional performance calculation device according to claim 2, wherein the performance calculation unit calculates the section modulus excluding a cross section at the web that is perpendicular to the material axis direction of the H-shaped cross-section member and that falls within the range of the invalid web height d' obtained by equation (5) from the centroid of the web in the direction in which the first flange and the second flange face each other. where d is the inner diameter of the H-shaped cross section member, t ｗ is the thickness of the web, E is Young's modulus, F ｗ is the reference strength of the allowable stress of the web, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k ｂｗ is the buckling coefficient of the web when the H-section member is subjected to a uniform bending moment and undergoes local buckling. [Equation 4]

7. the external force is a shear force, The cross-sectional performance calculation device according to claim 1 , wherein the performance calculation unit calculates the cross-sectional performance by calculating a cross-sectional area.

8. The H-shaped cross-section member satisfies formula (6), The cross-sectional performance calculation device according to claim 7 , wherein the performance calculation unit calculates the entire cross section of the web perpendicular to the material axis direction of the H-shaped cross-section member as the cross-sectional area. where d is the inner diameter of the H-shaped cross section member, t ｗ is the thickness of the web, E is Young's modulus, F ｗ is the reference strength of the allowable stress of the web, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k ｓｗ is the buckling coefficient of the web when the H-section member is subjected to a pure shear force and buckles in shear. [Equation 5]

9. The H-shaped cross-section member satisfies formula (7), 8. The cross-sectional performance calculation device according to claim 7, wherein the performance calculation unit calculates the cross-sectional area excluding a cross section in the web that is perpendicular to the material axis direction of the H-shaped cross-section member and that is within the range of the invalid web height d' obtained by equation (8) from the centroid of the web in the direction in which the first flange and the second flange face each other. where d is the inner diameter of the H-shaped cross section member, t ｗ is the thickness of the web, E is Young's modulus, F ｗ is the reference strength of the allowable stress of the web, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k ｓｗ is the buckling coefficient of the web when the H-section member is subjected to a pure shear force and buckles in shear. [Equation 6]

10. A method for calculating cross-sectional properties of an H-shaped section member having a first flange, a second flange, and a web joined to the first flange and the second flange, a coefficient calculation step of calculating a buckling coefficient for each of the first flange, the second flange, and the web using an elastic buckling stress when the H-shaped section member locally buckles as a whole due to an external force acting on the H-shaped section member; a performance calculation step of calculating the cross-sectional performance of the H-shaped cross-section member using the buckling coefficient; A method for calculating cross-sectional performance.

11. the external force is a bending moment, The method for calculating cross-sectional performance according to claim 10 , wherein the performance calculation step calculates the cross-sectional performance by calculating a section modulus.

12. The H-shaped cross-section member satisfies formula (11), 12. The method for calculating cross-sectional performance according to claim 11, wherein in the performance calculation step, the section modulus is calculated for the entire cross section perpendicular to the material axis direction of the H-shaped cross-section member in the target flange, which is one of the first flange and the second flange. where b is half the width of the target flange, t ｆ is the thickness of the target flange, E is Young's modulus, F ｆ is the reference strength of the allowable stress of the target flange, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k ｂｆ is the buckling coefficient of the target flange when the H-shaped section member is subjected to a uniform bending moment and undergoes local buckling. [Equation 7]

13. The H-shaped cross-section member satisfies formula (12), The method for calculating cross-sectional properties according to claim 11 , wherein the performance calculation step calculates the section modulus for all cross sections in the web that are perpendicular to the material axis direction of the H-shaped cross-section member. where d is the inner diameter of the H-shaped cross section member, t ｗ is the thickness of the web, E is Young's modulus, F ｗ is the reference strength of the allowable stress of the web, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k ｂｗ is the buckling coefficient of the web when the H-section member is subjected to a uniform bending moment and undergoes local buckling. [Equation 8]

14. The H-shaped cross-section member satisfies formula (13), 12. The method for calculating cross-sectional performance according to claim 11, wherein in the performance calculation step, the section modulus is calculated for an effective flange width calculated by multiplying the right-hand side of equation (13) by the thickness of the target flange from a cross-section perpendicular to the material axis direction of the H-shaped cross-section member in the target flange, which is one of the first flange and the second flange, excluding the range exceeding the right-hand side of equation (13). where b is half the width of the target flange, t ｆ is the thickness of the target flange, E is Young's modulus, F ｆ is the reference strength of the allowable stress of the target flange, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k ｂｆ is the buckling coefficient of the target flange when the H-shaped section member is subjected to a uniform bending moment and undergoes local buckling. [Equation 9]

15. The H-shaped cross-section member satisfies formula (14), 12. The method for calculating cross-sectional performance according to claim 11, wherein in the performance calculation step, the section modulus is calculated excluding a cross section in the web that is perpendicular to the material axis direction of the H-shaped cross-section member and that falls within the range of the invalid web height d' obtained by equation (15) in the direction in which the first flange and the second flange face each other from the centroid of the web. where d is the inner diameter of the H-shaped cross section member, t ｗ is the thickness of the web, E is Young's modulus, F ｗ is the reference strength of the allowable stress of the web, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k ｂｗ is the buckling coefficient of the web when the H-section member is subjected to a uniform bending moment and undergoes local buckling. [Equation 10]

16. the external force is a shear force, The method for calculating cross-sectional performance according to claim 10 , wherein the performance calculation step calculates the cross-sectional performance by calculating a cross-sectional area.

17. The H-shaped cross-section member satisfies formula (16), 17. The method for calculating cross-sectional properties according to claim 16, wherein in the performance calculation step, the cross-sectional area is calculated as the entire cross section of the web perpendicular to the material axis direction of the H-shaped cross-section member. where d is the inner diameter of the H-shaped cross section member, t ｗ is the thickness of the web, E is Young's modulus, F ｗ is the reference strength of the allowable stress of the web, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k ｓｗ is the buckling coefficient of the web when the H-section member is subjected to a pure shear force and buckles in shear. [0011]

18. The H-shaped cross-section member satisfies formula (17), 17. The method for calculating cross-sectional performance according to claim 16, wherein in the performance calculation step, the cross-sectional area is calculated excluding a cross section in the web that is perpendicular to the material axis direction of the H-shaped cross-section member and that is within the range of the invalid web height d' obtained by equation (18) from the centroid of the web in the direction in which the first flange and the second flange face each other. where d is the inner diameter of the H-shaped cross section member, t ｗ is the thickness of the web, E is Young's modulus, F ｗ is the reference strength of the allowable stress of the web, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k ｓｗ is the buckling coefficient of the web when the H-section member is subjected to a pure shear force and buckles in shear. [0012]

19. A calculation program for calculating cross-sectional properties of an H-shaped cross-section member having a first flange, a second flange, and webs joined to the first flange and the second flange, the calculation program comprising: The calculation device, a coefficient calculation unit that calculates a buckling coefficient for each of the first flange, the second flange, and the web using an elastic buckling stress when the H-shaped cross-section member locally buckles as a whole due to an external force acting on the H-shaped cross-section member; a performance calculation unit that calculates the cross-sectional performance of the H-shaped cross-section member using the buckling coefficient; A cross-sectional performance calculation program that functions as a

20. the external force is a bending moment, The cross-sectional performance calculation program according to claim 19 , wherein the performance calculation unit calculates the cross-sectional performance by calculating a section modulus.

21. The H-shaped cross-section member satisfies formula (21), The cross-sectional performance calculation program according to claim 20, wherein the performance calculation unit calculates the section modulus for the entire cross section perpendicular to the material axis direction of the H-shaped cross-section member in a target flange that is one of the first flange and the second flange. where b is half the width of the target flange, t ｆ is the thickness of the target flange, E is Young's modulus, F ｆ is the reference strength of the allowable stress of the target flange, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k ｂｆ is the buckling coefficient of the target flange when the H-shaped section member is subjected to a uniform bending moment and undergoes local buckling. [0013]

22. The H-shaped cross-section member satisfies formula (22), 21. The cross-sectional performance calculation program according to claim 20, wherein the performance calculation unit calculates the section modulus for all cross sections in the web that are perpendicular to the material axis direction of the H-shaped cross-section member. where d is the inner diameter of the H-shaped cross section member, t ｗ is the thickness of the web, E is Young's modulus, F ｗ is the reference strength of the allowable stress of the web, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k ｂｗ is the buckling coefficient of the web when the H-section member is subjected to a uniform bending moment and undergoes local buckling. [0014]

23. The H-shaped cross-section member satisfies formula (23), The performance calculation unit calculates the section modulus for an effective flange width calculated by multiplying the right side of equation (23) by the thickness of the target flange from a cross section perpendicular to the material axis direction of the H-shaped cross section member in the target flange, which is one of the first flange and the second flange, excluding the range exceeding the right side of equation (23). where b is half the width of the target flange, t ｆ is the thickness of the target flange, E is Young's modulus, F ｆ is the reference strength of the allowable stress of the target flange, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k ｂｆ is the buckling coefficient of the target flange when the H-shaped section member is subjected to a uniform bending moment and undergoes local buckling. [Equation 15]

24. The H-shaped cross-section member satisfies formula (24), The cross-sectional performance calculation program according to claim 20, wherein the performance calculation unit calculates the section modulus excluding a cross section in the web that is perpendicular to the material axis direction of the H-shaped cross-section member and that falls within the range of the invalid web height d' obtained by equation (25) from the centroid of the web in the direction in which the first flange and the second flange face each other. where d is the inner diameter of the H-shaped cross section member, t ｗ is the thickness of the web, E is Young's modulus, F ｗ is the reference strength of the allowable stress of the web, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k ｂｗ is the buckling coefficient of the web when the H-section member is subjected to a uniform bending moment and undergoes local buckling. [0016]

25. the external force is a shear force, The cross-sectional performance calculation program according to claim 19 , wherein the performance calculation unit calculates the cross-sectional performance by calculating a cross-sectional area.

26. The H-shaped cross-section member satisfies formula (26), 26. The cross-sectional performance calculation program according to claim 25, wherein the performance calculation unit calculates the entire cross section of the web perpendicular to the material axis direction of the H-shaped cross-section member as the cross-sectional area. where d is the inner diameter of the H-shaped cross section member, t ｗ is the thickness of the web, E is Young's modulus, F ｗ is the reference strength of the allowable stress of the web, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k ｓｗ is the buckling coefficient of the web when the H-section member is subjected to a pure shear force and buckles in shear. [Equation 17]

27. The H-shaped cross-section member satisfies formula (27), 26. The cross-sectional performance calculation program according to claim 25, wherein the performance calculation unit calculates the cross-sectional area excluding a cross section in the web that is perpendicular to the material axis direction of the H-shaped cross-section member and that is within the range of the invalid web height d' obtained by equation (28) from the centroid of the web in the direction in which the first flange and the second flange face each other. where d is the inner diameter of the H-shaped cross section member, t ｗ is the thickness of the web, E is Young's modulus, F ｗ is the reference strength of the allowable stress of the web, α is a coefficient determined by the magnitude of geometric imperfections and residual stress, k ｓｗ is the buckling coefficient of the web when the H-section member is subjected to a pure shear force and buckles in shear. [Equation 18]

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