Buckling restraint brace

Abstract

To provide a buckling restraint brace enabling axial force added to a main core material to be adequately transmitted to an auxiliary core material and enabling necessary welding work and weld metal to be reduced.SOLUTION: A buckling restraint brace 1 comprises: a long main core material 10 with a plate portion 12 disposed on both ends thereof in a longer direction; and a long plate-like auxiliary core material 20 disposed on both ends in the longer direction of the main core material 10 so as to be along a longer direction of the main core material 10 and orthogonal to a plate surface of the plate portion 12 on the main core material 10. Out-of-plane deformation of the main core material 10 is restrained. The buckling restraint brace has a weld line W1 extending along an intersecting line between the plate portion 12 on the main core material 10 and the auxiliary core material 20. The weld line W1 is tapered toward outer side from inner side in the longer direction of the main core material 10.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a buckling restrained brace. [Background technology]

[0002] Buckling restrained braces are sometimes used for vibration control in buildings. Buckling restrained braces include a long main core material, long plate-shaped secondary core materials arranged at both ends of the main core material in the longitudinal direction, and arranged in a position along the longitudinal direction of the main core material and perpendicular to the plate surfaces of the plate-shaped portions located at both ends of the main core material in the longitudinal direction, and a restraining member that restricts out-of-plane deformation of the main core material. When a compressive axial force is generated in the main core material due to vibration load during an earthquake and the main core material is displaced in the plate thickness direction, the restraining member receives the load and suppresses the progression of buckling of the main core material. The lack of progression of buckling of the main core material improves the vibration control effect against earthquakes. A conventional example of such a buckling restraint brace is one in which both ends of the buckling restraint brace are equipped with connection parts that are connected to the structure on which it is to be installed, and the connection parts are arranged on both ends of the plate-shaped main core material and on plate-shaped secondary core materials erected on both the front and back sides of both ends of the plate-shaped main core material (for example, Patent Document 1). In Patent Document 1, by arranging connection parts on both the main core material and the secondary core material, the axial force of the buckling restraint brace can be shared between the main core material and the secondary core material. Incidentally, in the buckling restrained brace of Patent Document 1, a filler material is placed between the restraint member and the main core material, and a buffer material is placed between the welded portion and the filler material to prevent the welded portion joining the main core material and the secondary core material from interfering with the filler material. As a result, when the welded portion is displaced due to the application of a compressive force to the main core material, for example, the buffer material deforms to absorb the displacement of the welded portion. This prevents interference between the welded portion and the filler material. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7253665 Summary of the Invention [Problem to be solved by the invention]

[0004] In the buckling restrained brace of Patent Document 1, the welded portion that welds the main core material and the secondary core material has the same thickness over the entire length. In other words, the joint strength between the main core material and the secondary core material is the same over the entire length of the welded portion. Therefore, for example, if an attempt is made to form a welded metal wire with sufficient joint strength by performing multiple welding passes, work time is required for the number of welding passes, and an amount of weld metal corresponding to the number of passes is required. However, as a result of the inventors' investigations, it was found that when the axial force of the buckling restrained brace is shared between the main core material and the secondary core material, the stress transmission from the main core material to the secondary core material is dominated by the welded portion that extends linearly along the longitudinal direction of the main core material, particularly the inner portion. Therefore, if the welded portion has the same thickness over its entire length, as in the conventional method, there is a problem that there is waste of welding work and waste of weld metal.

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide a buckling restraint brace that enables the axial force applied to the main core material to be properly transmitted to the secondary core material, while reducing the welding time and amount of weld metal required when welding the secondary core material to the main core material. [Means for solving the problem]

[0006] <1> The buckling restraint brace of aspect 1 of the present invention comprises a long main core material having plate-shaped portions at both longitudinal ends, and a long, plate-shaped secondary core material arranged at both longitudinal ends of the main core material so as to run along the longitudinal direction of the main core material and perpendicular to the plate surfaces of the plate-shaped portions in the main core material.The buckling restraint brace restricts out-of-plane deformation of the main core material, and is characterized in that it has a weld line extending along the intersection line between the plate-shaped portions in the main core material and the secondary core material, and the weld line becomes thinner as it goes from the inner side to the outer side in the longitudinal direction of the main core material. Effect of the Invention

[0007] According to the present invention, a buckling restraint brace can be provided that enables the axial force applied to the main core material to be appropriately transmitted to the secondary core material while reducing the welding time and amount of weld metal required when welding the secondary core material to the main core material. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a side view of a buckling restrained brace according to an embodiment. [Diagram 2] FIG. 2 is a plan view of a buckling restraint brace according to an embodiment. [Diagram 3] 3 is a cross-sectional view of the line III-III shown in FIG. [Figure 4] 4 is a cross-sectional view of the IV-IV portion shown in FIG. [Diagram 5] FIG. 2 is a cross-sectional view of the VV portion shown in FIG. [Figure 6] FIG. 13 is a distribution diagram of the shear force applied to the welded portion between the main core material and the secondary core material in a buckling restraint brace. [Figure 7] 2 is a first example of an enlarged view of the periphery of the weld shown in FIG. 1. [Figure 8] 2 is a second example of an enlarged view of the periphery of the weld shown in FIG. 1 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] (About buckling restraint braces) DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A buckling restrained brace according to an embodiment of the present invention will now be described with reference to the drawings. The buckling restrained brace is used, for example, to reinforce a structure made up of columns and beams in a building. FIG. 1 is a side view of a buckling restraint brace 1 according to an embodiment. FIG. 2 is a plan view of the buckling restraint brace 1 according to the embodiment. FIG. 3 is a cross-sectional view taken along line III-III of FIG. FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. FIG. 5 is a cross-sectional view of the VV portion shown in FIG. FIG. 6 is a distribution diagram of the shear force applied to the welded portion W between the main core material 10 and the secondary core material 20 in the buckling restrained brace 1. FIG. 7 is a first example of an enlarged view of the periphery of the welded portion W shown in FIG. FIG. 8 is a second example of an enlarged view of the periphery of the welded portion W shown in FIG. As shown in FIGS. 1 to 5, the buckling restrained brace 1 includes a main core material 10, a secondary core material 20, a restraining member 30, a filling material 40, and an unbonded material 50.

[0010] The main core material 10 is a long member. In this embodiment, the main core material 10 is, for example, a long, plate-like member made of a steel plate. The main core material 10 reinforces the building by having both ends attached to the structure of the building. In this embodiment, the main core material 10 is made of a steel plate (flat steel). It is preferable that the main core material 10 is made of a steel material with a low yield point, such as an SN material (rolled steel material for architectural structures) or an LYP material (very low yield point steel material). In this case, the yield of the main core material 10 improves the earthquake energy absorption.

[0011] 1 and 2, the main core material 10 includes a narrow width portion 11, a plate-like portion 12, and a width-changing portion 13. Hereinafter, when there is no need to distinguish between the narrow width portion 11, the plate-like portion 12, and the width-changing portion 13, the main core material 10 will be illustrated or referred to as the main core material 10. Narrow width portion 11 is located in a portion including the center in the longitudinal direction of main core material 10, and has a constant cross-sectional shape perpendicular to the longitudinal direction of main core material 10. In this embodiment, narrow width portion 11 is a plate-like shape with a rectangular cross-section, as shown in Fig. 3. Alternatively, narrow width portion 11 is not limited to this, and may have other shapes, such as a cylindrical shape or a rectangular tube shape. The plate-like portions 12 are plate-like portions located at both ends of the main core material 10 in the longitudinal direction. The plate-like portions 12 have a width greater than that of the narrow portions 11. When the narrow portions 11 are cylindrical or the like, the width of the plate-like portions 12 is at least greater than the dimension of the narrow portions 11 in the direction along the width of the plate-like portions 12. In this embodiment, the plate-like portions 12 are shorter in the longitudinal direction than the narrow portions 11. In this embodiment, the width of the plate-like portions 12 is constant, but the width may be gradually increased toward the ends.

[0012] In this embodiment, the main core material 10 has a plasticized portion 10P that is located in a portion including the longitudinal center of the main core material 10 and is narrower than the portion protruding from the restraining member 30 described below. That is, the portion including the longitudinal center of the main core material 10 is narrow portion 11, and the longitudinal ends are plate-shaped portions 12. As a result, the second moment of area of ​​narrow portion 11 is smaller than the second moment of area of ​​plate-shaped portions 12, and the longitudinal center of the main core material 10 (narrow portion 11) becomes a region that is easily plasticized. Hereinafter, the region of the main core material 10 that is easily plasticized (narrow portion 11) is referred to as plasticized portion 10P.

[0013] As shown in FIG. 1, the width-changing portion 13 is a boundary region between the plate-like portion 12 and the narrow portion 11. In this embodiment, the width-changing portion 13 is plate-like like the plate-like portion 12. The width-changing portion 13 is formed continuously on both sides of the plasticized portion 10P in the longitudinal direction of the main core material 10. The width-changing portion 13 changes so that the plate width becomes larger from the inner side to the outer side in the longitudinal direction of the main core material 10. Tapered surfaces 13T are formed on both ends of the width-changing portion 13. The width-changing portion 13 absorbs, for example, an additional bending moment acting on the main core material 10. The angle A between the tapered surface 13T in the width-changing portion 13 and the longitudinal direction is preferably 30 degrees or less. This allows the compressive load input to the plate-like portion 12 from the structure to which the buckling restrained brace 1 is attached to be efficiently transmitted to the narrow portion 11.

[0014] In this embodiment, the plate thickness of the plate-shaped portion 12 of the main core material 10 is, for example, 12 mm or more and 16 mm or less. In this embodiment, the main core material 10 is a plate-shaped member. Therefore, the plate thickness of the entire main core material 10 may be 12 mm or more and 16 mm or less.

[0015] The secondary core material 20 is disposed at both ends of the main core material 10 in the longitudinal direction. The secondary core material 20 is, for example, a long, plate-like member made of a steel plate. As shown in Figs. 1 and 2, the secondary core material 20 is joined to the plate-like portion 12 of the main core material 10. The secondary core material 20 is provided on the front and back surfaces of the plate-like portion 12 (surfaces facing the plate thickness direction of the main core material 10). In the portion of the main core material 10 in the longitudinal direction where the secondary core material 20 is disposed, the main core material 10 has a cross-shaped cross section perpendicular to the longitudinal direction, as shown in Figs. 4 and 5. 1 and 2, the secondary core material 20 is disposed in a position along the longitudinal direction of the main core material 10 and perpendicular to the plate surface of the plate-like portion 12. A position along the longitudinal direction of the main core material 10 means that the longitudinal direction of the secondary core material 20 is disposed along the longitudinal direction of the main core material 10. By disposing the secondary core material 20 in the main core material 10 in this manner, both ends of the main core material 10 are reinforced, and the portion of the main core material 10 where the secondary core material 20 is disposed in the longitudinal direction is prevented from bending in the plate thickness direction. In this embodiment, the secondary core material 20 and the plate-like portion 12 of the main core material 10 are joined by welding. The details of the welding between the secondary core material 20 and the plate-like portion 12 of the main core material 10 will be described later.

[0016] In this embodiment, the plate thickness of the plate-like portion 12 in the main core material 10 is the same as the plate thickness of the secondary core material 20. That is, the plate thickness of the secondary core material 20 is in the range of 12 mm or more and 16 mm or less, and is the same dimension as that of the plate-like portion 12 in the main core material 10. This allows the plate-like portion 12 and the secondary core material 20 to have the same characteristics, such as the amount of strain,. In this embodiment, the thickness of the plate-like portion 12 in the main core material 10 and the thickness of the secondary core material 20 are preferably measured by, for example, a vernier caliper.

[0017] 1, the end of the secondary core material 20 on the inner side in the longitudinal direction of the main core material 10 is located outside the boundary between the plasticized portion 10P and the width changing portion 13. This makes it possible to prevent the welded portion W between the plate-like portion 12 of the main core material 10 and the secondary core material 20 from overlapping the boundary between the plasticized portion 10P and the width changing portion 13 in the longitudinal direction of the main core material 10. Therefore, for example, it is possible to prevent the material properties of the boundary between the plasticized portion 10P and the width changing portion 13 from changing due to welding, making it difficult to properly transmit stress from the plasticized portion 10P to the width changing portion 13 in the main core material 10.

[0018] As shown in Figs. 1 and 2, the plate-like portion 12 of the main core material 10 and the secondary core material 20 each have a connection portion C at the outer end in the longitudinal direction of the main core material 10, which is connected to the structure on which the buckling restrained brace 1 is to be installed. The connection portion C is provided, for example, at the outer end of the plate-like portion 12 in the longitudinal direction of the main core material 10. In this embodiment, the connection portion C is, for example, a plate-like portion including a bolt hole. In this case, the buckling restrained brace 1 is attached to the building by a bolt (not shown) inserted into the bolt hole. As shown in Figs. 1 and 2, the connection portion C of the main core material 10 and the secondary core material 20 may have a plate width expanded at the end of the plate-like portion 12, for example, in order to ensure a plate width that allows the bolt hole to be formed. In that case, the width change portion 13 may also be located in the portion of the plate-like portion 12 where the plate width is expanded.

[0019] The restraining member 30 restricts out-of-plane deformation of the main core material 10. The restraining member 30 is a member that covers the outer periphery of the main core material 10 with both ends of the main core material 10 protruding. In this embodiment, the restraining member 30 is, for example, cylindrical. In other words, the portion of the main core material 10 other than both ends is housed inside the cylindrical restraining member 30. This makes it possible to distribute the load applied to the filler material 40 due to the deformation of the main core material 10, for example, to the filler material 40. The restraining member 30 is made of, for example, a steel material. The length of the longitudinal direction of the restraining member 30 is shorter than the length of the longitudinal direction of the main core material 10. Therefore, both ends of the main core material 10 in the longitudinal direction protrude from the restraining member 30.

[0020] The filler 40 is filled inside the restraining member 30. The filler 40 is filled between the main core material 10 and the restraining member 30. The filler 40 is concrete, mortar, or the like. The restraining member 30 and the filler 40 restrict deformation of the main core material 10 in directions other than the longitudinal direction (in-plane deformation and out-of-plane deformation). In order to prevent the filler 40 from leaking out from the ends of the restraining member 30, both end openings of the restraining member 30 are closed by lids (not shown).

[0021] In this embodiment, the crush strength of the filler 40 is equal to or greater than the maximum compressive stress that occurs in the filler 40 when the out-of-plane deformation of the main core material 10 reaches the maximum allowable deformation. Here, the maximum compressive stress is the stress that indicates the maximum value among the stresses that occur with distribution in the filler 40. In this embodiment, the crush strength of the filler 40 is, for example, 21 N / mm 2 The crushing strength of the filler 40 can be measured by the mortar strength test specified in JASS·5 (Standard Specifications for Building Construction·Commentary Chapter 5 (Reinforced Concrete)).

[0022] In this embodiment, the plasticized portion 10P does not have an opening, in other words, the filler 40 is filled without any gaps between the plasticized portion 10P of the main core material 10 and the restraining member 30. This creates a confining effect in the filler 40 located around the plasticized portion 10P, and can further improve the yield strength of the filler 40 located around the plasticized portion 10P.

[0023] 3 to 5, the unbond material 50 is interposed between the main core material 10 and the filler material 40, and allows relative movement between the main core material 10 and the filler material 40 by elastically deforming in accordance with the deformation of the main core material 10. In this way, the unbond material 50 restricts the main core material 10 and the filler material 40 from acting as one unit in the longitudinal direction. As a result, the filler material 40 holds the main core material 10 so that the axial force of the main core material 10 is not transmitted to the restraining member 30, i.e., so that the main core material 10 can move relative to the restraining member 30 in the longitudinal direction.

[0024] (Details of the welding between the secondary core material and the plate-shaped part of the main core material) In this embodiment, the secondary core material 20 and the plate-shaped portion 12 of the main core material 10 are joined by welding. At this time, as shown in Fig. 1 and Fig. 2, the welded portion W between the secondary core material 20 and the plate-shaped portion 12 includes a linear weld line W1 and a box weld line W2.

[0025] (straight weld line) The linear weld line W1 extends along the intersection line between the plate-shaped portion 12 of the main core material 10 and the secondary core material 20. That is, as shown in Fig. 1 and Fig. 2, the linear weld line W1 is formed on one side and the other side in the plate thickness direction of the main core material 10 and on one side and the other side in the plate thickness direction of the secondary core material 20. At this time, it is preferable that the thickness of each linear weld line W1 is formed symmetrically with respect to the main core material 10 or the secondary core material 20, respectively. Note that in this embodiment, the thickness of the linear weld line W1 refers to the cross-sectional area of ​​the linear weld line W1, and refers to the cross-sectional area of ​​a cross section perpendicular to the longitudinal direction of the main core material 10 as shown in Fig. 4 or Fig. 5.

[0026] In this embodiment, the leg length S1 of the linear weld line W1 in the main core material 10 and the leg length S2 of the secondary core material 20 in the longitudinal direction of the main core material 10 are the same. The leg length S1 of the straight weld line W1 in the main core material 10 is the dimension of the area where the straight weld line W1 contacts the main core material 10 in the plate width direction of the plate-shaped portion 12 of the main core material 10, as shown in Figure 4 or Figure 5. The leg length S2 of the straight weld line W1 in the secondary core material 20 is the dimension of the area where the straight weld line W1 contacts the secondary core material 20 in the plate width direction of the secondary core material 20, as shown in FIG. 4 or 5, in a cross section perpendicular to the longitudinal direction of the main core material 10 at the joint between the plate-like portion 12 of the main core material 10 and the secondary core material 20, the cross-sectional shape of the linear weld line W1 is an isosceles triangle. This makes it possible to make the path of stress transmission from the main core material 10 to the secondary core material 20 symmetrical with respect to the intersection line between the main core material 10 and the secondary core material 20.

[0027] In this embodiment, the linear weld line W1 includes an inner portion W1i and an outer portion W1o, as shown in FIGS. The inner side portion W1i is a portion of the linear weld line W1 that is located on the inner side in the longitudinal direction of the main core material 10. The outer side portion W1o is a portion of the linear weld line W1 that is located outward in the longitudinal direction of the main core material 10 relative to the inner side portion W1i.

[0028] When an earthquake occurs in a structure to which the buckling restrained brace 1 is attached, a compressive force is applied to the main core material 10 of the buckling restrained brace 1 via the structure. This generates a compressive stress in the main core material 10. The compressive stress generated in the main core material 10 is transmitted to the secondary core material 20 via the welded portion W. At this time, a shear force is applied to the welded portion W.

[0029] At this time, as shown in the shear force distribution curve Sf in Fig. 6, the shear force generated in the inner side portion W1i is relatively high, and the shear force generated in the outer side portion W1o is relatively low. In other words, the part of the linear weld line W1 that contributes greatly to the stress transmission from the main core material 10 to the secondary core material 20 is the inner side portion W1i. The part of the linear weld line W1 that contributes little to the stress transmission from the main core material 10 to the secondary core material 20 is the outer side portion W1o.

[0030] Therefore, in this embodiment, the linear weld line W1 has a shape corresponding to the distribution of shear force acting on the linear weld line W1 when a load is applied along the longitudinal direction of the main core material 10. That is, the inner side portion W1i of the linear weld line W1, to which a higher shear force is applied, is formed relatively thick in order to increase the joint strength between the main core material 10 and the secondary core material 20. In contrast, the outer side portion W1o of the linear weld line W1, to which a relatively lower shear force is applied, is formed relatively thin in order to reduce the amount of weld metal. That is, in the linear weld line W1, the outer side portion W1o shown in Fig. 5 is formed thinner than the inner side portion W1i shown in Fig. 4. That is, as shown in Fig. 4 and Fig. 5, in a cross-sectional view perpendicular to the longitudinal direction of the main core material 10, the cross-sectional area of ​​the outer side portion W1o is smaller than the cross-sectional area of ​​the inner side portion W1i. This makes it possible to reduce the amount of weld metal in the outer side portion W1o while maintaining sufficient joint strength in the inner side portion W1i.

[0031] In order to ensure the joining strength of the inner side portion, it is preferable to weld the inner side portion by, for example, full penetration welding or partial penetration welding. In order to reduce the welding time and weld metal of the outer side portion, it is preferable to weld the outer side portion by, for example, fillet welding. This can further improve productivity. Below, two examples will be described of the manner in which the thickness of the linear weld line W1 changes from the inner side portion W1i to the outer side portion W1o.

[0032] (First example of change in thickness of linear weld line) The thickness of the linear weld line W1 gradually decreases from the inner side to the outer side in the longitudinal direction of the main core material 10, as shown in Fig. 7. In this case, a step is formed at the boundary between the inner portion W1i and the outer portion W1o of the linear weld line W1. In this case, in order to prevent stress concentration from occurring at the boundary between the inner portion W1i and the outer portion W1o, it is preferable that a spherical portion Ws with a spherical outer circumferential surface is formed at the boundary between the inner portion W1i and the outer portion W1o, as shown in Fig. 7. The shape of the linear weld line W1 according to this embodiment is preferably formed, for example, by changing the number of welding passes or the number of welding layers when forming the linear weld line W1 by welding.

[0033] (Second example of change in thickness of linear weld line) 8, the thickness of the linear weld line W1 may change so as to continuously become thinner from the inner side to the outer side in the longitudinal direction of the main core material 10. In this case, the boundary between the inner side portion W1i and the outer side portion W1o of the linear weld line W1 is not visible. In this embodiment, the maximum leg length of the inner side portion W1i of the linear weld line W1 is preferably 1.5 times or more the minimum leg length of the outer side portion W1o. The shape of the linear weld line W1 according to this example is preferably formed, for example, by changing the welding speed (specifically, the moving speed of the tip of the melting electrode) when forming the linear weld line W1 by welding.

[0034] (Length of inner side part) 7 and 8, in this embodiment, the length L1 of the inner portion W1i is preferably set so that, for example, when the maximum axial force expected in the buckling restrained brace 1 is applied, the shear force can be borne by the outer portion W1o in addition to the inner portion W1i. In other words, the length L1 of the inner portion W1i is preferably set so that, for example, the peak point of the shear force distribution curve Sf shown in Fig. 6 is outward in the longitudinal direction of the main core material 10. 7 and 8, in this embodiment, the length L1 of the inner side portion W1i of the linear weld line W1 in the longitudinal direction of the main core material 10 is preferably 40% or less of the length L2 of the secondary core material 20. In this embodiment, the length L1 of the inner side portion W1i refers to the distance from a connection between the boxing weld line W2 and the inner side portion W1i, which will be described later, to the boundary between the inner side portion W1i and the outer side portion W1o. This makes it possible to appropriately reduce the time required for welding and the amount of weld metal while adequately securing the length L1 of the inner side portion W1i, which contributes relatively greatly to stress transmission from the main core material 10 to the secondary core material 20. In this embodiment, the length L1 of the inner side portion W1i is preferably measured by, for example, a straight edge.

[0035] (Leg length of inner side part) In this embodiment, the leg length So of the outer portion W1o of the linear weld line W1 is, for example, about 6 mm. The leg length Si of the inner portion W1i of the linear weld line W1 is, for example, about 9 to 20 mm. More specifically, the leg length So of the portion of the outer portion W1o of the linear weld line W1 that has the shortest leg length So is, for example, about 6 mm. The leg length Si of the portion of the inner portion W1i of the linear weld line W1 that has the longest leg length Si is, for example, about 9 to 20 mm. That is, in the present embodiment, the leg length Si of the inner portion W1i of the linear weld line W1 is 1.5 times or more the leg length So of the outer portion W1o, which makes it easier to ensure the joint strength of the inner portion W1i. In this embodiment, the leg length So and the leg length Si are preferably measured by, for example, a straight edge.

[0036] (About the end of the outer side part) 7 or 8, an outer end W1oe, which is an end of an outer portion W1o of the linear weld line W1, may be spaced apart from an edge of the main core material 10. In other words, the linear weld line W1 does not have to be formed at an edge of the main core material 10. That is, the main core material 10 and the secondary core material 20 do not have to be welded to each other at the end of the main core material 10 in the longitudinal direction. This makes it possible to further reduce the time and weld metal required for the welding operation when welding the main core material 10 and the secondary core material 20 together.

[0037] (Regarding the presence or absence of grooves in welded sections) Here, for example, if the plate-like portion 12 of the main core material 10 and the secondary core material 20 have a plate thickness of 30 mm or more, it may not be possible to ensure sufficient joint strength between the plate-like portion 12 and the secondary core material 20. Therefore, when the plate-like portion 12 of the main core material 10 and the secondary core material 20 have a plate thickness of 30 mm or more, it is preferable to provide a groove B in the inner portion W1i of the linear weld line W1, as shown in Fig. 4. This makes it possible to ensure sufficient joint strength in the inner portion W1i even when the plate thickness is large.

[0038] (turned weld line) As shown in FIG. 1, FIG. 7, or FIG. 8, the wrapping weld line W2 is an end of the secondary core material 20, and is located around the end of the main core material 10 on the inner side in the longitudinal direction. In this embodiment, the wrapping weld line W2 is a part of the welded portion W that is formed in a U-shape along the end of the secondary core material 20 on the inner side in the longitudinal direction of the main core material 10 and one side and the other side in the plate thickness direction of the secondary core material 20. That is, in this embodiment, the boundary parts between the end of the secondary core material 20 on the inner side in the longitudinal direction of the main core material 10 and each of the one side and the other side in the plate thickness direction of the secondary core material 20 are welded by wrapping. The length L3 of the part of the wrapping weld line W2 along the longitudinal direction of the main core material 10 is, for example, about the length of the plate-shaped portion 12 of the main core material 10 and the plate thickness of the secondary core material 20. In order to ensure the joining strength between the main core material 10 and the secondary core material 20, the wrapping weld line W2 is preferably formed by, for example, full penetration welding.

[0039] In this embodiment, the boxing weld line W2 and the straight weld line W1 are formed in separate processes. That is, the process of forming the boxing weld line W2 and the process of forming the straight weld line W1 are separate processes. In this embodiment, the linear weld line W1 is formed continuously with the box weld line W2. That is, the ends of the box weld line W2 and the linear weld line W1 are continuous with each other. Therefore, in a state after the main core material 10 and the auxiliary core material 20 are welded, the boundary between the box weld line W2 and the linear weld line W1 is not visible. In this way, by forming the box weld line W2 and the linear weld line W1 continuously, the shear force applied near the boundary between the box weld line W2 and the linear weld line W1 can be borne by the box weld line W2 and the linear weld line W1 in cooperation with each other. The main core material 10 and the secondary core material 20 are welded together by the welded portion W having the above-described configuration.

[0040] The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, although the connection parts C have been described as bolt holes, this is not limiting. That is, the connection parts C provided in the plate-like parts 12 of the main core material 10 and the secondary core material 20 may be parts that are butt-welded to a member on the structure side. Alternatively, the connection parts C provided in the plate-like parts 12 of the main core material 10 and the secondary core material 20 may be through holes formed for pin-joining to a member on the structure side. Furthermore, when the thickness of the linear weld line W1 changes stepwise, the linear weld line W1 may have a plurality of steps at the portion where the thickness changes.

[0041] Also, although the thickness of the linear weld line W1 has been described as being changed by the number of welding passes, the number of weld layers, or the welding speed, this is not limited thereto. That is, for example, after the plate-like portion 12 of the main core material 10 and the secondary core material 20 are welded together by forming a linear weld line W1 of a constant thickness, the linear weld line W1 may be trimmed to change the thickness of the linear weld line W1.

[0042] Furthermore, the buckling restrained brace 1 according to this embodiment has been described as restricting deformation in directions other than the longitudinal direction of the main core material 10 by the restraining members 30 and the filler materials 40, but this is not limited to the above. In other words, deformation in directions other than the longitudinal direction of the main core material 10 may be restricted, for example, by arranging steel plates or wood on both sides of the main core material 10 in the plate thickness direction. Furthermore, in a portion of the longitudinal direction of the main core material 10 in the region including the outer end portion W1oe of the linear weld line W1 and its periphery, the region may be thicker than an adjacent portion on the inner side in the longitudinal direction of the main core material 10 from the outer end portion W1oe. In addition, although the secondary core material 20 has been described as being disposed in a position perpendicular to the plate surface of the plate-like portion 12, this is not limited thereto. That is, the secondary core material 20 and the plate-like portion 12 may be disposed so as to be substantially perpendicular to each other. "Substantially perpendicular" means that the crossing angle between the secondary core material 20 and the plate-like portion 12 is in the range of 85 degrees to 95 degrees.

[0043] The above-described embodiments are specific examples of the following inventions. That is, according to the buckling restrained brace of this embodiment, the linear weld line has a shape corresponding to the distribution of shear force acting on the linear weld line when a load is applied along the longitudinal direction of the main core material. For example, by thickening a portion of the linear weld line that contributes relatively greatly to stress transmission from the main core material to the secondary core material, the joint strength of that portion can be ensured and stress can be appropriately transmitted from the main core material to the secondary core material. By thinning a portion of the linear weld line that contributes relatively little to stress transmission from the main core material to the secondary core material, the time required for welding that portion and the amount of weld metal used for that portion can be reduced. Therefore, the productivity of the buckling restrained brace can be improved.

[0044] Here, the portion of the linear weld line that contributes more to stress transmission from the main core material to the secondary core material is the inner side portion, and the portion of the linear weld line that contributes less to stress transmission from the main core material to the secondary core material is the outer side portion. Therefore, the outer side portion is formed thinner than the inner side portion. In other words, the inner side portion is formed thicker than the outer side portion. This ensures the joint strength of the inner side portion and allows appropriate stress transmission from the main core material to the secondary core material. Furthermore, by forming the outer side portion thin, the time required for welding the outer side portion and the amount of weld metal used for the outer side portion can be reduced. Therefore, the productivity of the buckling restrained brace can be improved.

[0045] In addition, in the longitudinal direction of the main core material, the outer end portion, which is the end portion of the outer side portion of the linear weld line, is separated from the edge of the main core material. This makes it possible to further reduce the time and weld metal required for welding, particularly around the outer end portion that contributes little to stress transmission, among the outer side portions of the linear weld line that contribute little to stress transmission from the main core material to the secondary core material. This makes it possible to further improve the productivity of the buckling restrained brace.

[0046] Furthermore, in the longitudinal direction of the main core material, the length of the inner portion of the linear weld line is 40% or less of the length of the secondary core material, which allows the time required for welding and the amount of weld metal to be appropriately reduced while ensuring a sufficient length of the inner portion that contributes relatively greatly to the transfer of stress from the main core material to the secondary core material.

[0047] In addition, the leg length of the inner side portion is 1.5 times or more the leg length of the outer side portion, which makes it easier to ensure the joining strength of the inner side portion.

[0048] In addition, the thickness of the linear weld line is changed so as to become gradually thinner from the inner side to the outer side in the longitudinal direction of the main core material. Such a shape can be formed, for example, by changing the number of welding passes or the number of welding layers when forming the linear weld line by welding. Therefore, the thickness of the linear weld line can be changed in a relatively easy manner without performing any special process.

[0049] Also, the thickness of the linear weld line changes, for example, so as to become continuously thinner from the inner side to the outer side in the longitudinal direction of the main core material. Such a shape can be formed, for example, by changing the welding speed when forming the linear weld line by welding. Therefore, the thickness of the linear weld line can be changed in a relatively easy manner without performing a special process. Furthermore, compared with the case where the weld thickness is changed stepwise, the distribution of the shear stress applied to the linear weld line can be changed smoothly. Also, by preventing the occurrence of a step between the inner side portion and the outer side portion, it is possible to prevent stress concentration at the step.

[0050] The secondary core material further includes a weld line located around an end of the secondary core material on the inner side in the longitudinal direction of the main core material. This makes it possible to ensure the joint strength around the end of the secondary core material on the inner side in the longitudinal direction of the main core material. The linear weld line is formed continuously with the weld line. This makes it possible for the weld line and the linear weld line to cooperate to bear a relatively large shear force acting on the end of the secondary core material on the inner side in the longitudinal direction of the main core material. This makes it possible to reduce the shear stress generated in the weld line and the linear weld line. This makes it possible to improve the durability of the welded portion between the main core material and the secondary core material, for example.

[0051] In addition, the thickness of the plate-like portion of the main core material is the same as the thickness of the secondary core material. This allows the plate-like portion and the secondary core material to have the same characteristics, such as the amount of strain, when stress is transmitted from the main core material to the secondary core material. This makes it possible to prevent deformation of the linear weld line, for example, caused by the difference in the amount of strain between the plate-like portion and the secondary core material.

[0052] In addition, in the longitudinal direction of the main core material, the leg length of the linear weld line in the secondary core material is the same as the leg length in the main core material. This makes it possible to make the path of stress transmission from the main core material to the secondary core material symmetrical with respect to the intersection line between the main core material and the secondary core material. This makes it possible to more appropriately transmit stress from the main core material to the secondary core material.

[0053] Here, when the end of the secondary core material on the inside in the longitudinal direction of the main core material is positioned so as to overlap the boundary between the plasticized portion and the width-changing portion, the welded portion between the end of the secondary core material and the main core material will overlap the boundary between the plasticized portion and the width-changing portion. This will cause a change in the material properties of the boundary between the plasticized portion and the width-changing portion in the main core material, which may cause the stress to be difficult to transfer properly from the plasticized portion to the width-changing portion in the main core material. Therefore, the end of the secondary core material on the inner side in the longitudinal direction of the main core material is positioned outside the boundary between the plasticized portion and the width-changing portion. This arrangement can prevent the aforementioned cause from making it difficult to properly transmit stress from the plasticized portion to the width-changing portion. Therefore, stress can be properly transmitted from the plasticized portion of the main core material to the width-changing portion.

[0054] In addition, the main core material and the secondary core material have connection parts at their outer ends in the longitudinal direction of the main core material for connection to the structure on which the buckling restraint brace is to be installed, which makes it easier to connect the buckling restraint brace to the structural part.

[0055] Furthermore, a groove is provided on the inner side portion of the linear weld line, which makes it easier to ensure the joining strength of the inner side portion.

[0056] In addition, a spherical portion Ws with a spherical outer circumferential surface is formed at the boundary between the inner side portion and the outer side portion, which allows the shape to smoothly change from the inner side portion to the outer side portion, thereby making it possible to prevent stress concentration from occurring in the portion between the inner side portion and the outer side portion.

[0057] In addition, within the scope of the invention, the components in the above-described embodiments may be replaced with well-known components, and the above-described modified examples may be combined as appropriate. [Explanation of symbols]

[0058] 1. Buckling Restrained Brace 10 Main core material 10P plasticization part 11 Narrow section 12 Plate-shaped part 13 Width change section 13T tapered surface 20 Secondary core material 30 Restraining member 40 Filler 50 Unbonded material A Angle B opening C connection part S1, S2, Si, So lead lengths W welding part W1 straight welding line W1i inner side part W1o outer side part W1oe outer side end W2 circumferential welding line Ws spherical part

Claims

1. A long main core material having plate-shaped portions at both ends in a longitudinal direction; a longitudinally extending, plate-shaped secondary core material disposed at both ends of the longitudinal direction of the main core material so as to extend along the longitudinal direction of the main core material and to be perpendicular to the plate surface of the plate-shaped portion of the main core material; A buckling restraint brace in which out-of-plane deformation of the main core material is restricted, a weld line extending along an intersection line between the plate-shaped portion of the main core material and the secondary core material, The weld line becomes thinner from the inner side to the outer side in the longitudinal direction of the main core material. A buckling restrained brace characterized by:

2. In the longitudinal direction of the main core material, an outer end portion, which is an end portion on the outer side of the weld line, is spaced apart from an edge of the main core material.

2. The buckling restrained brace of claim 1.

3. The weld line is an inner side portion located on the inner side in the longitudinal direction of the main core; an outer side portion located on the outer side of the main core material in a longitudinal direction relative to the inner side portion; Including, In the longitudinal direction of the main core material, the length of the inner side portion of the weld line is 40% or less of the length of the secondary core material.

2. The buckling restrained brace of claim 1.

4. The weld line is an inner side portion located on the inner side in the longitudinal direction of the main core; an outer side portion located on the outer side of the main core material in a longitudinal direction relative to the inner side portion; Including, The leg length of the inner side portion of the weld line is 1.5 times or more than the leg length of the outer side portion of the weld line.

2. The buckling restrained brace of claim 1.

5. The inner side portion is provided with a groove.

2. The buckling restrained brace of claim 1.

6. The plate thickness of the plate-shaped portion of the main core material is the same as the plate thickness of the secondary core material.

2. The buckling restrained brace of claim 1.

7. In the longitudinal direction of the main core material, the leg length of the weld line in the secondary core material is the same as the leg length of the weld line in the main core material.

7. The buckling restrained brace of claim 6.

8. The secondary core member further includes a weld line located around an end portion of the secondary core member on an inner side in the longitudinal direction of the primary core member, The weld line is formed continuously to the turn weld line. The buckling restrained brace according to any one of claims 1 to 7.

9. The main core material is It is plate-shaped along its entire length, a plasticized portion located in a range including a center in a longitudinal direction of the main core material and having a constant cross-sectional shape perpendicular to the longitudinal direction of the main core material; a plate-shaped width changing portion that is formed continuously on both sides of the plasticized portion in the longitudinal direction of the main core material and has a plate width that changes so as to become larger from the inner side to the outer side in the longitudinal direction of the main core material; Equipped with An end portion of the secondary core material on an inner side in a longitudinal direction of the main core material is located outside a boundary between the plasticized portion and the width changing portion. The buckling restrained brace according to any one of claims 1 to 7.

10. The main core material and the secondary core material are provided with connection portions at outer ends in the longitudinal direction of the main core material, the connection portions being connected to a structure on which the buckling restraint brace is to be installed. The buckling restrained brace according to any one of claims 1 to 7.

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