Welded h-shaped steel beam, and manufacturing method thereof

Abstract

To provide a welded H-shaped steel beam capable of improving anti-deformation performance of the beam ends by reducing the concentration of stress and strain at the bottom of the scallop while improving production efficiency.SOLUTION: A beam web 11 includes a scallop 14 and a cutout 16 that forms a through hole 21 penetrating the beam web 11 in the thickness direction between the beam flange 12 and the same. The beam flange 12 has a bevel 25 at one end. In the extension direction of the beam web 11, out of the two ends of the welded portions 41a and 41b, the ends P3 and P3' that are proximal to the end that is joined to another structure is in the same position as the inner wall surface 16b located distally from one end joined to another structure out of the inner wall surfaces 16a and 16b constituting the through hole 21. Defining the distance from the groove shoulder 25a to the ends P3 and P3' is Lb, the distance Lb satisfies the following equation (1):SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a welded H-shaped steel beam and a manufacturing method thereof. [Background technology]

[0002] In welding a column to a beam, a scalloping method is commonly used, in which an H-shaped steel beam with a scallop formed at the end of the beam web is welded to a column using a backing metal (see Patent Document 1). The scallop is a circular, semicircular, or other notch provided at the end of the beam web in order to, for example, turn-weld the beam web to the beam flange during the manufacturing process of the welded H-shaped steel beam. When such a welded H-shaped steel beam is welded to a column, it has been found that stress tends to concentrate at the intersection between the end face of the beam web facing the scallop and the inner surface of the beam flange (hereinafter referred to as the scallop bottom).

[0003] In recent years, instead of making the shape of the above-mentioned scallop a quarter-circular arc shape, for example, it has been considered to make it a composite arc shape combining two arcs of different radii, such as an arc with a radius of 35 mm and an arc with a radius of 10 mm, and to reduce the concentration of stress and strain by making the cross-sectional changes of the beam flange and beam web near the bottom of the scallop gentler (see non-patent document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7195081 [Non-patent literature]

[0005] [Non-Patent Document 1] Steel Construction Technical Guidelines - Factory Fabrication, 6th Edition, Section 4.8, Scalloping, pp. 235-253, January 2018 Summary of the Invention [Problem to be solved by the invention]

[0006] In welding a beam web having the above-described compound arc-shaped scallop to a beam flange, after box welding, it is necessary to perform a process of cutting the box-welded portion smoothly against the inner surface of the beam flange using a grinder or the like. However, box welding not only requires advanced skills but also has the drawback of being labor-intensive. Furthermore, cutting using a grinder or the like places a heavy burden on the work and may damage the beam flange during cutting. For example, if the beam flange is damaged, the damaged area must be repaired or the beam flange must be remanufactured, resulting in increased manufacturing costs and construction time. Therefore, there is a strong demand for a welded H-shaped steel beam that can reduce the occurrence of stress and strain concentrations at the bottom of the above-described scallop without box welding or the cutting process after box welding.

[0007] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a welded H-shaped steel beam that can improve manufacturing efficiency and the deformation performance of the beam end by reducing the concentration of stress and strain at the bottom of the scallop, as well as a manufacturing method thereof. [Means for solving the problem]

[0008] A welded H-shaped steel beam according to one aspect is a welded H-shaped steel beam having a beam web and a beam flange welded to the beam web, wherein the beam web has a scallop provided at one end joined to another structure and at the end welded to the beam flange in the width direction of the beam web, and a notch provided at a position away from the scallop bottom in the extending direction of the beam web in the extending direction of the beam web, and forming a through hole penetrating the thickness direction of the beam web between the scallop bottom and the beam flange, and the beam flange has a groove at one end joined to the other structure, and of both ends in the extending direction of the beam web of the welded part, the end proximal to the one end joined to the other structure is located at the same position as the inner wall surface that is distal from the one end joined to the other structure in the extending direction of the beam web, of the inner wall surfaces that constitute the through hole, and the distance in the extending direction from the shoulder of the groove to the end proximal to the weld part is defined as L. b When this is done, the distance L b is characterized by satisfying the following equation (1):

number

[0009] Furthermore, it is preferable that the range from the scallop bottom to the inner wall surface that constitutes the through hole that is proximal to the one end that is joined to another structure is a range that does not require welding.

[0010] Furthermore, it is preferable that an area defining member for defining a welding area is inserted through the through hole when the beam web and the beam flange are welded together.

[0011] The length of the notch in the extending direction is preferably 20 mm to 35 mm, and the width of the notch in the height direction of the beam web is preferably 5 mm or more.

[0012] In addition, a manufacturing method of a welded H-shaped steel beam according to one aspect is a manufacturing method of a welded H-shaped steel beam having a beam web and a beam flange, wherein the beam web has a scallop provided at one end to be joined to another structure and at an end to be welded to the beam flange in the width direction of the beam web, and a notch provided in the extending direction of the beam web at a position away from the scallop bottom in the extending direction of the beam web and forming a through hole penetrating through the thickness direction of the beam web between the scallop bottom and the beam flange, the beam flange has a groove at one end to be joined to another structure, and of both ends in the extending direction of the beam web of the welded joint, the end proximal to the one end to be joined to the other structure is located at the same position as the inner wall surface that is distal from the one end to be joined to the other structure in the extending direction of the beam web, and the distance in the extending direction from the shoulder of the groove to the end proximal to the welded part is defined as L. b When this is done, the distance L b The beam web and the beam flange are welded together so that the following equation (2) is satisfied.

number

[0013] It is also preferable that the beam web and the beam flange are welded together with an area defining member that defines the welding area being inserted into the through hole. [Effects of the Invention]

[0014] According to the present disclosure, it is possible to improve manufacturing efficiency and also improve the deformation performance of the beam end by reducing the concentration of stress and strain at the bottom of the scallop. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a schematic diagram showing an example of the configuration of an end portion of a welded H-shaped steel beam according to this embodiment. [Figure 2] FIG. 2 is an enlarged view showing an example of the structure of the end portion of the lower beam flange of a welded H-shaped steel beam. [Figure 3] FIG. 3 is a schematic diagram showing an example of a joint structure between a column and an H-shaped steel beam, in which a shear plate fixed to the column is joined to the beam web. [Figure 4] FIG. 4 is a schematic diagram showing an example of a joint structure in which a column and an H-shaped steel beam are welded together. [Figure 5] FIG. 5 is a schematic diagram showing an example of the positions of the welded portions between the beam web and the beam flange. [Figure 6] FIG. 6 is an end view taken along line AA in FIG. [Figure 7] FIG. 7 is a schematic diagram showing an example of a manufacturing process for a welded H-shaped steel beam. [Figure 8] FIG. 8 is a schematic end view showing an example of a yield line that occurs when the distance from the groove shoulder to the end on the proximal side of the welded portion between the beam web and the beam flange is increased. [Figure 9] FIG. 9 is a schematic end view showing an example of a yield line that occurs when the distance from the groove shoulder to the proximal end of the welded portion between the beam web and the beam flange is shortened. [Figure 10] FIG. 10 is a schematic diagram showing an example of the configuration of a T-shaped frame used as a test specimen. [Figure 11] FIG. 11 is a schematic diagram showing an example of a case where a scallop is formed so that the opposing end faces are a combination of an arc-shaped wall surface and a wall surface that forms an acute angle with the inner surface of the beam flange. DETAILED DESCRIPTION OF THE INVENTION

[0016] The welded H-shaped steel beam shown in this embodiment will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing an example of the configuration of the end of a welded H-shaped steel beam in this embodiment. FIG. 2 is an enlarged view showing an example of the structure of the end of a lower beam flange of a welded H-shaped steel beam. FIGS. 1 and 2 illustrate a welded H-shaped steel beam in which a pair of beam flanges are arranged above and below a beam web. In the following description, the welded H-shaped steel beam may be simply referred to as an H-shaped steel beam.

[0017] The H-shaped steel beam 10 is composed of a beam web 11 and a pair of beam flanges 12, 13. Of the pair of beam flanges 12, 13, the beam flange 12 is welded to the lower end of the beam web 11, and the beam flange 13 is welded to the upper end of the beam web 11.

[0018] In the extension direction of the beam web 11 (the Y-axis direction in FIG. 1), a scallop 14 is provided at the lower end of the beam web 11 at the end joined to the column 51 (see FIG. 3). The shape of the scallop 14 is, for example, a combination of a quarter-circular arc 14a and a rectangle 14b. The angle θ1 formed between the end face 14c facing the scallop 14 and the inner surface 12b of the beam flange 12 is, for example, 90°.

[0019] In addition, a scallop 15 is provided at the upper end of the beam web 11 at the end joined to the column 51 (see FIG. 3) in the extension direction of the beam web 11. The shape of the scallop 15 is the same as the shape of the scallop 14. Note that the scallops 14 and 15 are symmetrical with respect to a straight line CL that passes through the midpoint of the beam web 11 in the width direction (Z-axis direction in FIG. 1) and is parallel to the extension direction of the beam web 11.

[0020] A notch 16 is provided at the lower end of the beam web 11 at a position away from the scallop 14 in the extension direction of the beam web 11. The notch 16 is rectangular and extends from the lower end surface 11a to the upper end surface 11b of the beam web 11. Similarly, a notch 17 is provided at the upper end of the beam web 11 at a position away from the scallop 15 in the extension direction of the beam web 11.

[0021] The cutout portion 16 forms a through hole 21 penetrating the thickness direction of the beam web 11 between the cutout portion 16 and the beam flange 12 abutting against the lower end surface 11a of the beam web 11. A ceramic tab 30, which will be described later, is inserted into the through hole 21. That is, the cross-sectional shape of the through hole 21 in the YZ plane is the same as the cross-sectional shape perpendicular to the extension direction of the ceramic tab 30. Note that the cross-sectional shape of the through hole 21 does not need to be the same as the cross-sectional shape perpendicular to the extension direction of the ceramic tab 30 (for example, the X-axis direction in FIG. 6 ), as long as the ceramic tab 30 can abut against the inner wall surface 16b of the cutout portion 16 and the inner surface 12b of the beam flange 12.

[0022] The cutout portion 17 forms a through hole 22 penetrating in the thickness direction (X-axis direction in FIG. 1) of the beam web 11 between the cutout portion 17 and the beam flange 13 abutting against the upper end surface 11b of the beam web 11. The cutout portion 17 has a shape that is line-symmetrical to the cutout portion 16 with respect to the above-mentioned straight line CL.

[0023] The cutout 16 has two inner wall surfaces 16a, 16b extending in the vertical direction (the Z-axis direction in FIG. 2) and a ceiling surface 16c perpendicular to the two inner wall surfaces 16a, 16b in the vertical direction. The two inner wall surfaces 16a, 16b are, for example, parallel to the XZ plane. The two inner wall surfaces 16a, 16b constituting the cutout 16 may be parallel to each other, or may be inclined at a predetermined angle with respect to the XZ plane.

[0024] In the above-mentioned cutout portion 16, for example, the distance from the lower end surface 11a of the beam web 11 to the ceiling surface 16c, i.e., the depth of the cutout portion 16, is preferably, for example, 20 mm or more and 35 mm or less. Also, the distance between the two inner wall surfaces 16a, 16b extending in the vertical direction, i.e., the width of the cutout portion 16, is preferably, for example, 5 mm or more.

[0025] A plurality of insertion holes 23 are arranged in a matrix at the end of the beam web 11. Note that FIG. 1 illustrates an example in which seven insertion holes 23 are provided in the width direction of the beam web 11 and two in the extension direction of the beam web 11, for a total of 14 insertion holes 23, but the number of insertion holes 23 is not limited to this. As shown in FIG. 3, bolts 53 are inserted into the insertion holes 23 to be used when joining the beam web 11 to a shear plate 52 fixed to a column 51. Note that, as shown in FIG. 4, if the shear plate 52 is not joined to the beam web 11, there is no need to provide the insertion holes 23 in the beam web 11.

[0026] 1 and 2, the beam flanges 12, 13 are elongated members welded to, for example, the widthwise ends of the beam web 11. Hereinafter, in the beam flanges 12, 13 welded to both widthwise ends of the beam web 11, the surfaces that the beam flanges 12, 13 face will be referred to as the inner surface, and the surface opposite the inner surface will be referred to as the outer surface.

[0027] Of these beam flanges 12, 13, a groove 25 is provided at the end in the extension direction (Y-axis direction in FIG. 1 ) of the beam flange 12 located below from the tip surface 12a to the inner surface 12b of the beam flange 12. The groove 25 is inclined from the outer surface 12c of the beam flange 12 toward the inner surface 12b. Furthermore, a groove 26 is provided at the end of the beam flange 13 located above from the tip surface 13a to the outer surface 13c of the beam flange 13.

[0028] The grooves 25, 26 provided in the beam flanges 12, 13 are provided to obtain the necessary penetration amount in the welded joint between the column 51 (see FIG. 3 or FIG. 4) and the beam flanges 12, 13. In other words, by providing the grooves 25, 26, the strength of the area where the column 51 and the beam flanges 12, 13 are welded and joined (hereinafter referred to as the welded area) is ensured.

[0029] The shapes of the grooves 25, 26 provided in the beam flanges 12, 13 (the angles of the grooves 25, 26, the depths of the grooves 25, 26, etc.) are set appropriately based on the strength of the welded portions, etc.

[0030] As described above, the through hole 21 is formed by butting the beam web 11 and the beam flange 12 together. The ceramic tab 30 is inserted into the through hole 21 during welding. Similarly, the through hole 22 is formed by butting the beam web 11 and the beam flange 13 together. The ceramic tab 30 is inserted into the through hole 22 during welding.

[0031] The ceramic tab 30 is a member that defines the positions of the ends P3, P3' of the welded portions 41a, 41b, which are proximal to the end of the H-shaped steel beam 10 joined to the column 51, in the extension direction of the H-shaped steel beam (Y-axis direction in FIG. 1 ). Hereinafter, the ends P3, P3' proximal to the end of the H-shaped steel beam 10 joined to the column 51 will be simply referred to as "ends P3, P3'." Although not shown, the ceramic tab 30 also defines the positions of the ends (not shown) proximal to the welded portions 42a, 42b with respect to the end of the H-shaped steel beam 10 joined to the column 51. Note that, in the extension direction of the H-shaped steel beam, the positions of the ends proximal to the welded portions 42a, 42b are the same as the ends P3, P3'.

[0032] The ceramic tab 30 is a refractory material made by adding a binder to powder mainly composed of silicon dioxide and several types of metal oxides, forming it into a flat plate, and firing it at 1000°C or higher. Here, the ceramic tab 30 corresponds to the range defining member recited in the claims. Note that although the ceramic tab 30 is exemplified as the range defining member, a steel tab can also be used.

[0033] 5 and 6, when the ceramic tab 30 is inserted into the through hole 21, one end 30a of the ceramic tab 30 protrudes from the end face 11c of the beam web 11, and at the same time, the other end 30b of the ceramic tab 30 protrudes from the end face 11d opposite to the end face 11c of the beam web 11. When the beam web 11 and the beam flange 12 are welded together, the ceramic tab 30 is held in the inserted state in the through hole 21, and is pulled out of the through hole 21 after the welding is completed.

[0034] Here, in the height direction of the H-shaped steel beam 10 (Z-axis direction in FIG. 5), the height of the ceramic tab 30 should be longer than the distance from the inner surface 12b of the beam flange 12 to the toes P1, P1' of the welded portions 41a, 41b on the end faces 11c, 11d of the beam web 11, in order to obtain a stable welded shape. Also, the protrusion amount of both ends 30a, 30b of the ceramic tab 30 from the beam web 11 should be longer than the distance from the end faces 11c, 11d of the beam web 11 to the toes P2, P2' of the welded portions 41a, 41b on the inner surface 12b of the beam flange 12, in order to obtain a stable welded shape.

[0035] According to this, the positions of the ends P3, P3' in the extension direction of the H-shaped steel beam 10 are defined in the weld metal deposited by welding the beam flange 12 and the beam web 11 together.

[0036] The above-mentioned H-shaped steel beam 10 is manufactured by the following manufacturing method. First, as shown in Figure 7(a), the inner surface 12b of the lower beam flange 12 is abutted against the lower end surface 11a of the beam web 11. In this state, the ceramic tab 30 is inserted into the through hole 21 formed by the beam flange 12 and the notch 16 of the beam web 11.

[0037] As shown in Figure 7(b), with the ceramic tab 30 inserted into the through hole 21, the beam web 11 and the beam flange 12 are welded together using a welding machine 45. Here, methods such as gas shielded arc welding and submerged arc welding are used to weld the beam web 11 and the beam flange 12 together. After the weld-joining, the ceramic tab 30 is extracted from the through hole 21.

[0038] As a result, as shown in Figure 6, for example, of both ends of the welded portions 41a, 41b in the extension direction of the beam web 11, the ends P3, P3' that are proximal to the end of the H-shaped steel beam 10 that is joined to the column 51 are aligned with the inner wall surface 16b of the cutout portion 16. Note that the range Ra1 (see Figure 2) from the scallop bottom 14d to the ends P3, P3' is an area where no welding is performed. Here, the scallop bottom 14d is the area where the end face 14c of the scallop 14 and the inner surface 12b of the beam flange 12 intersect.

[0039] In this embodiment, when the beam web 11 and the beam flange 12 are welded together, the ends P3, P3' are located at the same position as the inner wall surface 16b of the cutout portion 16 in the extension direction of the beam web 11. However, it is sufficient that the ends P3, P3' are located at the same position as the ridge line (not shown) between the inner wall surface 16b of the cutout portion 16 and the lower end surface 11a of the beam web 11.

[0040] After the beam web 11 and the beam flange 12 are welded together, as shown in FIG. 7(c), the beam web 11 and the beam flange 13 are welded together in the same procedure as the welding of the beam web 11 and the beam flange 12.

[0041] Although the beam flange 12 and the beam flange 13 are welded to the beam web 11 in this order, the order in which they are welded to the beam web 11 does not have to be limited to this.

[0042] Next, the positions of the ends P3 and P3' will be described. In the following, in the H-shaped steel beam 10 using the beam flange 12 with the groove 25 formed on the inside, the distance in the extension direction from the shoulder portion (hereinafter referred to as the groove shoulder) 25a of the groove 25 of the beam flange 12 to the ends P3 and P3' on the proximal side of the welded portions 41a and 41b of the beam web 11 and the beam flange 12 is defined as L. b Let's say.

[0043] Generally, the boundary between the ends P3, P3' and the inner surface 12b of the beam flange 12 is discontinuous in shape, and stress and strain tend to concentrate locally in this area. As a result, the boundary between the ends P3, P3' and the inner surface 12b of the beam flange 12 tends to become the starting point for plastic deformation and cracks.

[0044] As shown in Figure 8, for example, the distance L b is long, that is, when the ends P3 and P3' are moved away from the groove shoulder 25a of the H-shaped steel beam 10, a plasticized region of the beam flange 12 is secured, and the plastic strain on the inner surface 12b of the beam flange 12 is dispersed. Therefore, the crack that occurs at the ends P3 and P3' propagates in the width direction of the beam flange 12, following the propagation path of the yield lines L1 and L1' shown in Figure 8, and the beam flange 12 fractures.

[0045] On the other hand, as shown in Figure 9, the distance L b When the length P3, P3' is short, that is, when the ends P3, P3' are close to the groove shoulder 25a of the H-shaped steel beam 10, the plasticized region of the beam flange 12 generated around the ends P3, P3' is concentrated in a position close to the groove shoulder 25a of the H-shaped steel beam 10, and the plastic strain of the inner surface 12b of the beam flange 12 is difficult to distribute. In addition, both ends 61a, 61b of the welded portion 61 between the beam flange 12 and the column 51 are discontinuous in shape, and stress and strain tend to concentrate locally at both ends 61a, 61b of the welded portion 61.

[0046] As a result, the cracks that occur at the ends P3, P3' not only propagate in the thickness direction of the beam flange 12, but also connect with cracks at both ends 61a, 61b of the welded portion 61 between the beam flange 12 and the column 51, following the propagation path of the yield lines L2, L2' shown in Figure 9, causing the beam flange 12 to fracture.

[0047] In order to obtain excellent plastic deformation performance of the H-shaped steel beam 10, it is necessary to separate the ends P3 and P3' from the groove shoulder 25a of the H-shaped steel beam 10 so that the yield line L2 occurs before the yield line L1. b is set to satisfy the following equation (3).

[0048]

number

[0049] Here, the fully plastic bending moment M p1 is calculated from the following equation (4) based on the condition that the entire cross section of the beam flanges 12, 13 at the yield lines L1, L1' reaches the yield stress σy.

number

[0050] In addition, in the present invention, the fully plastic bending moment M p2 was newly derived by applying the plane stress state and the Mises yield criterion to the entire cross section of the beam flanges 12 and 13 at the yield lines L2 and L2'. p2 is shown in the following equation (5).

number

[0051] However, the above-mentioned full plastic bending moment M p1 ,M p2 is a value obtained by ignoring the stress on the beam web 11, that is, the stress is not easily transmitted to the beam web 11 due to the influence of deformation of the column 51, etc.

[0052] By the way, the above-mentioned distance L b If the relationship of the above formula (3) is satisfied, there is no need to impose a special restriction on the upper limit value. For example, the distance L b As the distance L increases, the area where the inner surface 12b of the beam flange 12 is not restrained by the beam web 11 increases. The increase in the area makes it easier for local buckling to occur in the beam flange 12 when the beam flange 12 is subjected to a compressive force. Therefore, b For example, it is preferable that the distance is 250 mm or less.

[0053] In order to demonstrate the effects of the present invention, a structural test and a finite element analysis were carried out using a T-shaped frame (see FIG. 10) consisting of a square steel pipe column 71 and an H-shaped steel beam 72 as a test specimen 70. Hereinafter, an example in which the H-shaped steel beam 10 described in this embodiment is used as the H-shaped steel beam 72 will be referred to as an invention example.

[0054] The H-shaped steel beam 10 used in the specimens and analysis models of the invention examples is made of SN490B steel, and the dimensions of the H-shaped steel beam 10 are H-600 x 200 x 16 x 25 (unit: mm).

[0055] In the example of the invention, the distance L from the groove shoulder 25a of the beam flange 12 to the ends P3 and P3' is b The distance L b is a value that satisfies the above-mentioned equation (3).

[0056] In addition, a case where an H-shaped steel beam using a composite circular scallop as recommended in Non-Patent Document 1 was used as the above-mentioned H-shaped steel beam 72 was used as an example (hereinafter referred to as a comparative example) for comparison with the above-mentioned invention example, and structural experiments and finite element analysis similar to those of the invention example were carried out.b was set at just under 10 mm.

[0057] The structural test was carried out to verify that the H-shaped steel beam 10 had a full plastic bending strength M p In this test, a stress Q1 is applied to the H-shaped steel beam 10 with alternating positive and negative voltages, resulting in a displacement (=3δp) three times the displacement δp of the free end of the beam when the beam reaches a certain displacement, and the number of cycles until fracture is measured. In addition, the finite element method analysis is carried out to determine the maximum value of plastic strain when a stress Q2 is applied monotonically until the displacement of the free end of the H-shaped steel beam 10 reaches 3δp.

[0058] In the structural test, the number of cycles to fracture Nf in the comparative example was Nf = 5. On the other hand, the number of cycles to fracture Nf in the inventive example was Nf = 9. That is, the distance L that satisfies the relationship of the above-mentioned formula (1) b It was found that in this case, the plastic deformation performance of the H-shaped steel beam 10 is improved.

[0059] Furthermore, in the finite element analysis, the maximum value of equivalent plastic strain in the comparative example was 0.29. On the other hand, the maximum value of equivalent plastic strain in the inventive example was 0.26. That is, the distance L b It was found that by setting the above, the plastic strain occurring on the inner surface 12b of the beam flange 12 is reduced.

[0060] As described above, from the results of the structural test and the finite element method analysis, the distance L from the groove shoulder 25a of the beam flange 12 to the ends P3 and P3' is b It has been demonstrated that by setting the above equation (3) to satisfy, the concentration of stress and strain at the ends P3 and P3' is alleviated, and excellent plastic deformation performance of the H-shaped steel beam 10 is obtained.

[0061] In this embodiment, the distance L b However, it is also possible to set the distance Lb so as to satisfy, for example, the following equation (6):

number

[0062] In this embodiment, the shape of the scallop 14 is, for example, a combination of a quarter-circular arc 14a and a rectangle 14b. However, the shape of the scallop 14 does not have to be limited to a combination of a quarter-circular arc 14a and a rectangle 14b. As shown in Fig. 11, the scallop 81 can be provided so that the end face 82 facing the scallop 81 is a combination of an arc-shaped wall surface 82a and a wall surface 82b that is inclined so that the angle θ1 between the arc-shaped wall surface 82a and the inner surface 12b of the beam flange 12 is an acute angle.

[0063] In this embodiment, the details of the column 51 to which the H-shaped steel beam 10 is joined are not described. However, the column 51 may be, for example, a column having a polygonal or box-shaped cross section perpendicular to the extending direction of the column. Also, the column may be made of a circular steel pipe or an H-shaped steel. Furthermore, the column does not have to be limited to a steel frame, but may be a concrete-filled steel pipe in which concrete is filled inside the steel frame to enhance earthquake resistance. Furthermore, the column may be a steel-framed reinforced concrete column, which is a composite structure of steel and concrete.

[0064] Furthermore, the connection between the H-shaped steel beam and the column is basically an internal diaphragm type. However, there are no particular restrictions on this connection type, and other connection types such as through diaphragm type and external diaphragm type can also be used.

[0065] <Summary of effects> The welded H-shaped steel beam 10 of this embodiment is a welded H-shaped steel beam 10 having a beam web 11 and a beam flange 12 welded to the beam web 11, and the beam web 11 has a scallop 14 provided at one end that is joined to another structure and at the end that is welded to the beam flange 12 in the width direction of the beam web 11, and a scallop 14 provided at a position away from the scallop bottom 14d in the extension direction of the beam web 11 and at the end that is welded to the beam flange 12. The beam flange 12 has a notch 16 that forms a through hole 21 that penetrates in the thickness direction of the beam web 11 between the beam flange 12 and the beam web 11, and the beam flange 12 has a groove 25 at one end that is joined to another structure, and in the extending direction of the beam web 11, the ends P3, P3' that are welded are located at the same position as the inner wall surface 16b that is located distal from the one end that is joined to the other structure, among the inner wall surfaces 16a, 16b that constitute the through hole 21, and the distance from the groove shoulder 25a to the ends P3, P3' is defined as L. b When this is done, the distance L b satisfies the above-mentioned equation (6).

[0066] This allows for the omission of the need for turn welding on the scallop bottom 14d and cutting work using a grinder or the like during welding, thereby significantly improving the manufacturing efficiency of the H-shaped steel beam. In addition, the concentration of stress and strain at the scallop bottom 14d and the ends P3 and P3' can be reduced, making it possible to obtain excellent plastic deformation performance in the H-shaped steel beam 10.

[0067] Furthermore, it is preferable that the range Ra1 from the scallop bottom 14d to the inner wall surfaces 16a, 16b that constitute the through hole 21, from one end that is joined to another structure to the inner wall surface 16b that is distal, is a range in which welding is not performed.

[0068] This eliminates the need for a turn joint when welding the beam web 11 and the beam flange 12, allowing for efficient welding. Furthermore, by eliminating the need for a weld joint from the area from the through hole 21 to the scallop bottom 14d, this area supports the beam flange 12 from the inside when the beam flange 12 is subjected to compressive stress. This prevents local buckling of the beam flange 12. [Explanation of symbols]

[0069] 10 Welded H-beam 11 Beam Web 12,13 Beam flange 14,71,74 Scallop 16,17 Notch 21, 22 Through holes 25 Bevel 25a Bevel shoulder 30 Ceramic tab (area defining member) 41a, 41b Welded parts L1,L2 yield line L b Distance from shoulder of groove to bottom of scallop P3, P3' proximal end

Claims

1. A welded H-shaped steel beam having a beam web and a beam flange welded to the beam web, The beam web has a scallop provided at one end joined to another structure and at an end welded to the beam flange in the width direction of the beam web, and a notch provided at a position apart from the scallop bottom in the extension direction of the beam web and forming a through hole penetrating the beam web in the thickness direction between the scallop and the beam flange, The beam flange has a groove at one end to be joined to the other structure, Of both ends of the welded portion in the extending direction of the beam web, the end that is proximal to the one end that is joined to the other structure is at the same position as the inner wall surface that is distal to the one end that is joined to the other structure in the extending direction of the beam web, among the inner wall surfaces that constitute the through hole, The distance in the extension direction from the shoulder of the groove to the proximal end of the weld portion is L ｂ When the distance L ｂ A welded H-shaped steel beam characterized by satisfying the following formula (1). [Equation 1] however, Symbol L: The distance in the extension direction from the inflection point of the bending moment acting in the extension direction of the welded H-shaped steel beam to the shoulder of the groove provided in the beam flange. Symbol B ｂ : Beam flange width is.

2. A welded H-shaped steel beam as described in claim 1, characterized in that the range from the scallop bottom to the inner wall surface of the through hole that is proximal to the one end that is joined to the other structure is a range in which the welding joint is not performed.

3. 2. A welded H-shaped steel beam according to claim 1, wherein a range defining member that defines a welding range is inserted through the through hole when the beam web and the beam flange are welded together.

4. 2. A welded H-shaped steel beam according to claim 1, wherein the length of the notch in the extension direction is 20 mm or more and 35 mm or less.

5. 2. A welded H-shaped steel beam according to claim 1, wherein the width of the notch in the height direction of the beam web is 5 mm or more.

6. A method for manufacturing a welded H-shaped steel beam having a beam web and a beam flange, The beam web has a scallop provided at one end joined to another structure and at an end welded to the beam flange in the width direction of the beam web, and a notch provided at a position apart from the scallop bottom in the extension direction of the beam web and forming a through hole penetrating the beam web in the thickness direction between the scallop and the beam flange, The beam flange has a groove at one end to be joined to the other structure, Of the two ends in the extension direction of the beam web of the welded portion where the welded joint is performed, the end that is proximal to the one end that is joined to the other structure is at the same position as the inner wall surface that is distal from the one end that is joined to the other structure, in the extension direction of the beam web, of the inner wall surfaces that constitute the through hole, and the distance in the extension direction from the shoulder of the groove to the proximal end of the welded portion is L ｂ When the distance L ｂ The method for manufacturing a welded H-shaped steel beam is characterized in that the beam web and the beam flange are welded together so that the following formula (2) is satisfied. [Equation 2] however, Symbol L: The distance in the extension direction from the inflection point of the bending moment acting in the extension direction of the welded H-shaped steel beam to the shoulder of the groove provided in the beam flange. Symbol B ｂ : Beam flange width is.

7. 7. The method for manufacturing welded H-shaped steel beams according to claim 6, wherein the beam web and the beam flange are welded together with a range defining member that defines the welding range being inserted into the through hole.

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