Assembled welded component

Abstract

To control buckling mode and buckling direction of assembled welded components.SOLUTION: A steel brace 20 includes a web plate and a flange plate 40 that forms a corner part with the web plate and is assembled and welded at the corner part; on both sides in the width direction of the flange plate 40, a pair of notches 50 are provided which reduce the width of the middle part of the flange plate 40 in the material axis direction and are not in alignment with the material axis direction.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an assembled welded member.

Background Art

[0002] A brace type vibration damping damper including a brace core material and a sheath member into which the brace core material is inserted is known (for example, see Patent Document 1).

[0003] Also, an unbonded brace including a core brace and a cylindrical stiffener into which the core brace is inserted is known (for example, see Patent Document 2).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] For example, in a built-up H-shaped steel constituting a brace or the like, when assembling and welding a web plate and a flange plate, a welded joint may occur.

[0006] Here, at the welded joint, when the built-up H-shaped steel is axially compressed and deformed, stress is likely to concentrate due to irregularities in the shape of the welded surface or the like. Therefore, if a welded joint exists in an assembled welded member such as a built-up H-shaped steel, the fatigue life of the assembled welded member may be reduced.

[0007] As a countermeasure, for example, when axially compressed and deformed, the strain distribution generated in the assembled welded member is obtained by analysis or the like, and the welded joint is positioned in a region where the strain is relatively small.

[0008] However, when the assembled welded member buckles during axial compression deformation, the buckling direction and buckling mode vary due to uncertain factors such as the initial irregularities and manufacturing non-uniformities of the assembled welded member. Therefore, it is difficult to obtain the strain distribution of the assembled welded member during axial compression deformation through analysis or the like, and it is also difficult to identify the region where the strain is relatively small during axial compression deformation.

[0009] In view of the above facts, an object of the present invention is to control the buckling mode and buckling direction of the assembled welded member.

Means for Solving the Problems

[0010] The assembled welded member according to claim 1 includes a first plate and a second plate that forms a corner with the first plate and is assembled and welded at the corner. On both sides in the width direction of the second plate, a pair of notches are provided that narrow the width of the middle portion in the material axis direction of the second plate and are arranged offset in the material axis direction.

[0011] According to the assembled welded member according to claim 1, the second plate forms a corner with the first plate, and the corner is assembled and welded.

[0012] Here, a pair of notches are provided on both sides in the width direction of the second plate. By this pair of notches, the width of the middle portion in the material axis direction of the second plate is narrowed. As a result, buckling can be generated in the middle portion of the second plate during axial compression deformation of the assembled welded member.

[0013] In addition, the pair of notches are arranged offset in the material axis direction of the second plate. Thereby, the buckling mode of the assembled welded member can be controlled to the secondary mode, and the buckling direction of the middle portion can also be controlled in a predetermined direction.

[0014] Further, by controlling the buckling mode and buckling direction of the assembled welded member, the strain distribution of the assembled welded member during axial compression deformation can be obtained by analysis or the like. That is, by analysis or the like, a region with relatively small strain can be obtained during the axial compression deformation of the assembled welded member.

[0015] The assembled welded member according to claim 2 is the assembled welded member according to claim 1, wherein a welding joint of the assembled welding is located in a region formed in the second plate by the pair of notches and having relatively small strain during buckling.

[0016] According to the assembled welded member according to claim 2, a welding joint of the assembled welded part is located in a region formed in the second plate by a pair of notches and having relatively small strain during buckling. Thereby, during the axial compression deformation of the assembled welded member, breakage or the like of the welding joint is suppressed, so that a decrease in the fatigue life of the assembled welded member can be suppressed.

[0017] The assembled welded member according to claim 3 is the assembled welded member according to claim 1 or claim 2, wherein the first plate is a web plate, and the second plate is a flange plate assembled and welded to both ends of the web plate, respectively.

[0018] According to the assembled welded member according to claim 3, the first plate is a web plate, and the second plate is a flange plate assembled and welded to both ends of the web plate, respectively. That is, the assembled welded member has an H-shaped cross section.

[0019] Thus, in the present invention, the buckling mode and buckling direction of the assembled welded member having an H-shaped cross section can be controlled.

[0020] The assembled welded member according to claim 4 is the assembled welded member according to any one of claims 1 to 3, which is a steel brace.

[0021] According to the assembled welded member according to claim 4, the buckling mode and buckling direction of the steel brace can be controlled.

Effect of the Invention

[0022] As described above, according to the present invention, the buckling mode and buckling direction of the assembled welded member can be controlled.

Brief Description of the Drawings

[0023]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0024] Hereinafter, an embodiment will be described with reference to the drawings.

[0025] (Steel Brace) FIG. 1 shows a structure 10 provided with a steel brace 20 according to the present embodiment. The structure 10 is a portal frame structure having a pair of columns 12 and upper and lower beams 14 installed on the pair of columns 12.

[0026] Note that the structural type of the frame 10 is not particularly limited, and for example, it may be a reinforced concrete structure, a steel-reinforced concrete structure, or a steel structure.

[0027] The steel brace (hysteretic brace) 20 is, for example, of a single-flow type and is arranged diagonally on the frame 10. Both ends of the steel brace 20 in the material axis direction are joined to the corner (joint portion) of the frame 10 via a pair of brackets 16. This steel brace 20 undergoes axial compression deformation (axial compression deformation) along with the shear deformation of the frame 10 during an earthquake.

[0028] Note that the steel brace 20 is not limited to the single-flow type, and for example, it may be of an X-type, A-type, K-type, etc., or a horizontal brace. Also, the steel brace 20 is an example of an axial compression member that undergoes axial compression deformation.

[0029] As shown in FIGS. 2, 3(A), and 3(B), the steel brace 20 is formed of built-up H-shaped steel. This steel brace 20 has a web plate 30 and a pair of flange plates 40 provided at both ends in the width direction of the web plate 30.

[0030] In other words, the steel brace 20 has a pair of flange plates 40 facing each other and a web plate 30 connecting the pair of flange plates 40. The web plate 30 and the pair of flange plates 40 are formed of metal plates such as steel plates (flat steel) and are assembled and welded in a factory or the like.

[0031] Specifically, as shown in FIGS. 3(A) and 3(B), both ends of the web plate 30 are respectively abutted against the central portion in the width direction of the facing surface 40T of the pair of flange plates 40. The corners formed by the web plate 30 and the pair of flange plates 40 are continuously welded by fillet welding or partial penetration welding, respectively.

[0032] Note that the web plate 30 is an example of the first plate, and the flange plate 40 is an example of the second plate. Further, the steel brace 20 is an example of an assembled welded member (assembled welded steel).

[0033] Here, in continuous welding, the weld length (bead length) that can be continuous in one weld is determined according to the length of the welding rod and the like. Therefore, in the present embodiment, a weld joint (bead joint) WJ (see FIG. 2) exists in the assembled weld part W between the web plate 30 and the pair of flange plates 40. The position of the weld joint WJ will be described later.

[0034] (A pair of notches) As shown in FIG. 2, a pair of notches 50 are provided on both sides in the width direction (arrow Y direction) of the middle part in the material axis direction (arrow X direction) of each flange plate 40. The pair of notches 50 are formed in a concave shape that narrows the width of the flange plate 40. Each notch 50 has a bottom 50A and rising parts 50B on both sides.

[0035] The bottom 50A is arranged along the material axis direction (arrow X direction) of the flange plate 40 and constitutes the width direction end of the narrow part 42 described later. Rising parts 50B are provided at both ends of the bottom 50A respectively.

[0036] The rising part 50B curves outward in the width direction of the flange plate 40 from the bottom 50A toward the wide part 44 described later. The rising part 50B constitutes the width direction both ends of the widening part 46 described later.

[0037] The pair of notches 50 are substantially the same in shape and size. Also, as will be described later, the pair of notches 50 are arranged offset in the material axis direction of the flange plate 40. By this pair of notches 50, a narrow part 42, a pair of wide parts 44, and a pair of widening parts 46 are formed on the flange plate 40.

[0038] (Narrow part, wide part, widening part) The flange plate 40 has a narrow-width portion 42, a pair of wide-width portions 44, and a pair of widened portions 46. The narrow-width portion 42 has a substantially constant width h and constitutes the middle portion of the flange plate 40 in the material axis direction. The wide-width portions 44 are provided on both sides of the narrow-width portion 42 in the material axis direction. In other words, the narrow-width portion 42 is provided between the pair of wide-width portions 44.

[0039] The pair of wide-width portions 44 have a substantially constant width h and constitute both end sides of the flange plate 40 in the material axis direction. The pair of wide-width portions 44 are joined to the structure 10 via the pair of brackets 16 (see FIG. 1) described above.

[0040] The pair of wide-width portions 44 are wider in width h than the narrow-width portion 42. In other words, the narrow-width portion 42 is narrower in width h than the pair of wide-width portions 44. As a result, when the steel brace 20 undergoes axial compression deformation, the narrow-width portion 42 is more likely to plastically deform than the pair of wide-width portions 44. The pair of wide-width portions 44 and the narrow-width portion 42 are connected by a pair of widened portions 46.

[0041] The pair of widened portions 46 increase in width h as they go from the narrow-width portion 42 toward the wide-width portions 44. Both end portions in the width direction of each widened portion 46 are constituted by the rising portions 50B of the notch 50. That is, both end portions in the width direction of the widened portion 46 are curved end portions that curve outward from the narrow-width portion 42 toward the wide-width portions 44.

[0042] (Control of Buckling Direction and Buckling Mode) In the present embodiment, by shifting the pair of notches 50 in the material axis direction of the flange plate 40, the buckling direction and buckling mode of the narrow-width portion 42 are controlled. Specifically, by shifting the pair of notches 50 by a predetermined amount G in the material axis direction of the flange plate 40, as shown by the arrow S, the narrow-width portion 42 is controlled to buckle in a secondary mode in a predetermined direction.

[0043] Here, as described above, the pair of notches 50 are arranged with a predetermined amount G of displacement in the material axis direction of the flange plate 40. As a result, when the flange plate 40 is viewed from the thickness direction, the pair of widened portions 46 are point-symmetrical with respect to the centroid C of the narrow-width portion 42. Note that the pair of flange plates 40 have the same shape (planar shape) when viewed from the thickness direction.

[0044] Also, in the widened portion 46, in the region where the pair of notches 50 are displaced (hereinafter referred to as the "displacement region G"), the cross-sectional loss on one side (arrow S side) in the width direction of the flange plate 40 is larger than the cross-sectional loss on the other side (opposite side of arrow S) with respect to the center line CL of the flange plate 40.

[0045] Also, as shown in FIGS. 4(A) and 4(B), in the cross-sectional view of the steel brace 20, in the displacement region G (see FIG. 2) of the widened portion 46, the flange plate 40 is asymmetric (left-right asymmetric) with respect to the weak axis Z of the steel brace 20.

[0046] More specifically, in the cross-sectional view of the steel brace 20, in the displacement region G of the widened portion 46, the distances a and b to both ends (rising portions 50B) in the width direction of the flange plate 40 are different with respect to the weak axis Z of the steel brace 20 (a > b). As a result, as described above, the narrow-width portion 42 is controlled to buckle in the secondary mode in a predetermined direction as indicated by the arrow S in FIG. 2.

[0047] (Analysis Results) FIG. 5 shows the analysis results of the displacement in the width direction (arrow Y direction) of the steel brace 20 at the time of buckling. As shown in FIG. 5, it can be seen that by shifting the pair of notches 50 by a predetermined amount G in the material axis direction of the flange plate 40, the narrow-width portion 42 buckles in the secondary mode in a predetermined direction.

[0048] In addition, Fig. 6 shows the analysis results of the strain distribution during buckling of the steel brace 20. As shown in Fig. 6, when the steel brace 20 undergoes axial compression deformation and the narrow-width portion 42 buckles in the secondary mode, a region where the strain is relatively small (hereinafter referred to as the "small-strain region R") is formed on the protruding side (arrow S side) of the narrow-width portion 42, that is, the tensile side of the narrow-width portion 42. This is because on the tensile side of the narrow-width portion 42, the compressive strain due to the axial compression deformation is offset by the tensile strain due to buckling.

[0049] In this embodiment, the welded joint WJ of the assembled welded portion W is located in the above-mentioned small-strain region R. Thereby, when the narrow-width portion 42 buckles, the stress on the welded joint WJ is reduced.

[0050] Note that the predetermined amount (displacement amount) G by which the pair of notches 50 are displaced in the material axis direction of the flange plate 40 exceeds the initial irregularities of the built-up H-shaped steel and manufacturing non-uniformities, etc. For example, it is preferably 5 mm or more. Also, the predetermined amount (displacement amount) G is set to 10 mm or less, for example.

[0051] (Function) Next, the function of this embodiment will be described.

[0052] First, the steel brace according to the comparative example will be described. Fig. 7 shows the analysis results of the displacement in the width direction (arrow Y direction) during buckling of the steel brace 100 according to the comparative example. Also, Fig. 8 shows the analysis results of the strain distribution during buckling of the steel brace 100 according to the comparative example.

[0053] The steel brace 100 according to the comparative example differs from the steel brace 20 (see Fig. 5) according to this embodiment in that the pair of notches 50 are not displaced in the material axis direction of the flange plate 40. Therefore, in the steel brace 100 according to the comparative example, the buckling direction and buckling mode during axial compression deformation vary due to uncertain factors such as the initial irregularities of the assembled welded members and manufacturing non-uniformities.

[0054] Therefore, it is difficult to obtain the strain distribution during axial compression deformation of the steel brace 100 according to the comparative example by analysis or the like, and it is also difficult to identify a region where the strain is relatively small during axial compression deformation.

[0055] In addition, in FIG. 7, as an example, the displacement in the width direction (arrow Y direction) when the steel brace 100 according to the comparative example buckles in the primary mode is shown as indicated by arrow S. Similarly, in FIG. 8, the strain distribution when the steel brace 100 according to the comparative example buckles in the primary mode is shown.

[0056] On the other hand, in FIG. 5, as described above, the analysis result of the displacement in the width direction (arrow Y direction) during buckling of the steel brace 20 according to the present embodiment is shown. Further, in FIG. 6, the analysis result of the strain distribution during buckling of the steel brace 20 according to the present embodiment is shown.

[0057] In the present embodiment, the pair of notches 50 are arranged with a predetermined amount G of displacement in the material axis direction of the flange plate 40. As a result, as indicated by arrow S, the buckling mode of the width-reduced portion 42 of the steel brace 20 can be controlled to a secondary mode in a predetermined direction.

[0058] Further, by controlling the buckling mode and buckling direction of the steel brace 20, as shown in FIG. 6, the strain distribution of the steel brace 20 during axial compression deformation can be obtained by analysis or the like. That is, by analysis or the like, a small-strain region R where the strain is relatively small during axial compression deformation of the steel brace 20 can be obtained.

[0059] By positioning the welded joint WJ of the assembly welded portion W in this small-strain region R, damage to the welded joint is suppressed during axial compression deformation of the steel brace 20. Therefore, a decrease in the fatigue life of the steel brace 20 can be suppressed.

[0060] (Modification example) Next, a modification example of the above embodiment will be described.

[0061] In the above embodiment, the rising portions 50B on both sides of the notch 50 are curved outward in the width direction of the flange plate 40 from the bottom portion 50A toward the wide portion 44. However, the rising portion 50B is not limited to being curved, and for example, it may be inclined outward in the width direction of the flange plate 40 from the bottom portion 50A toward the wide portion 44. Further, the rising portion 50B may be perpendicular to the bottom portion 50A. That is, the rising portion 50B and the bottom portion 50A may form a right angle.

[0062] Also, in the above embodiment, the welding joint WJ of the assembly welding portion W is located in the small strain region R. However, in the above embodiment, by shifting the pair of notches 50 in the material axis direction of the flange plate 40, it is only necessary that the buckling direction and buckling mode of the narrow portion 42 can be controlled, and it is not always necessary to position the welding joint WJ in the small strain region R. Further, the above embodiment is also applicable to the steel brace 20 without the welding joint WJ.

[0063] Also, in the above embodiment, the steel brace 20 is formed of built H-shaped steel. However, the steel brace is not limited to built H-shaped steel, and for example, it may be formed of an assembled welded member having a cross-sectional cruciform shape.

[0064] In the steel brace having a cross-sectional cruciform shape, for example, the ends of the pair of first plates are abutted against both sides of the second plate, and the corners formed by the second plate and the pair of first plates are respectively assembled and welded. In this steel brace, for example, a pair of notches are formed on both sides in the width direction of the second plate. Further, a pair of notches may be formed on both sides in the width direction of the second plate, and notches may be respectively formed on one end side (tip side) in the width direction of the pair of first plates protruding from the second plate.

[0065] Also, in the above embodiment, the assembled welded member is the steel brace 20. However, the assembled welded member is not limited to the steel brace 20. The assembled welded member may be a metal axial compression member that is axially compressed and deformed, and for example, it may be a chord member or a diagonal member of a truss structure.

[0066] The above describes one embodiment of the present invention. However, the present invention is not limited to such embodiments, and one embodiment and various modifications may be used in appropriate combination, and it goes without saying that the present invention can be implemented in various ways without departing from the gist of the present invention.

Explanation of Reference Numerals

[0067] 20 Steel Brace (Fabricated Welded Member) 30 Web Plate (First Plate) 40 Flange Plate (Second Plate) 50 Notch WJ Weld Joint

Claims

1. a first plate, a second plate forming a corner with the first plate and having the corner assembled and welded, comprising, on both sides in the width direction of the second plate, a pair of notches are provided which narrow the width of the middle portion in the material axis direction of the second plate and are arranged shifted in the material axis direction, an assembled welding member.

2. The welded joint of the assembled welding is located in a region formed in the second plate by the pair of notches and having relatively small strain during buckling. The assembled welding member according to Claim 1.

3. The first plate is a web plate, The second plate is a flange plate assembled and welded to both ends of the web plate respectively. The assembled welding member according to Claim 1.

4. being a steel brace, The assembled welding member according to any one of Claims 1 to 3.

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