Buckling-restrained brace

Abstract

To provide a buckling restraint brace capable of preventing the occurrence of parts falling off and areas that cannot be stiffened when the core material deforms while enjoying the same effect such as adjustment of the axial force of the core material using a conventional structure in which a spacer is inserted into a slit provided in the core material, and suppressing the strength decrease in the strong axis direction.SOLUTION: A buckling restraint brace 100 has a core material 10, and a pair of restraining materials 30 made of square steel pipes. The core material 10 has a wide part 12 on both ends and a narrow part 11 in the center, and a transition part 13 that connects the wide part 12 and the narrow part 11, and the width gradually becomes narrower toward the narrow part 11, and at the boundary P2 with the narrow part 11, the width is narrower than the narrow part 11. The narrow part 11 includes relatively wide multiple first narrow part 11A and narrow second narrow part 11B. The second narrow part 11B is the shrinkage margin when compression deformation. In the first narrow part 11A, two notches 16 extending from the left and right boundaries P2 and P1 are formed, and a margin 17 is provided in the center.SELECTED DRAWING: Figure 1

Description

Technical Field

[0005]

[0001] The present invention relates to a buckling restraint brace.

Background Art

[0002] Conventionally, as a brace for forming a building structure (column-beam structure, roof structure, etc.), a buckling restraint brace with buckling prevention measures has been applied. As the buckling restraint brace, there are various stiffening forms such as a form in which the periphery of a steel core material is stiffened only with steel plates, a form in which the periphery of a steel core material is stiffened with RC (Reinforced Concrete), and a form in which the periphery of a steel core material is covered with steel and mortar.

[0003] Here, Patent Document 1 proposes a buckling restraint brace in which a core material is restrained by a restraint material formed of a pair of square steel pipes, and a buckling restraint brace that does not cause local failure in the restraint material receiving a pressing force from the core material. Specifically, it is a buckling restraint brace including a core material having joints for joining to other members at both ends of a plate-like portion, and a restraint material disposed facing each surface orthogonal to the weak axis direction of the plate-like portion.

[0004] In this buckling restraint brace, slits are provided on the wide surface of the core material, and axial force adjustment (or yield strength adjustment) acting on the core material is performed by these slits. Due to these slits, when the core material receives an axial force (compressive force), high-order mode buckling occurs effectively in the weak axis direction of the core material. However, by providing slits on the wide surface, there is a trade-off relationship in that the strength in the strong axis direction of the core material decreases and high-order mode buckling occurs in the strong axis direction. In order to suppress this decrease in strength in the strong axis direction, spacers shorter than the slits in length are inserted into the slits.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] According to the buckling-restrained brace described in Patent Document 1, by providing slits in the wide surface of the core material and inserting spacers into the slits, it is possible to adjust the axial force of the core material while suppressing a decrease in strength in the strong axis direction.

[0007] Incidentally, in a configuration where a slit is provided on the wide surface of the core material and a separately manufactured, relatively short spacer is inserted into it, the length of the slit in the longitudinal direction is made longer than that of the spacer to prevent the predetermined compressive strain in the longitudinal direction of the core material due to the axial force (compressive force) acting during an earthquake from being hindered by the spacer. However, when buckling of higher-order modes occurs while the slit is compressed in the longitudinal direction in this way, there is a risk that the spacer may fall out of the slit due to its own weight. Furthermore, when buckling of higher-order modes occurs in the strong-axis direction of the core material, the spacer may be biased towards one end of the slit, increasing the gap on the other side of the slit and creating a region that is not stiffened by the spacer.

[0008] The present invention has been made in view of the above problems, and aims to provide a buckling-restrained brace that, while enjoying similar effects to the conventional structure in which a spacer is inserted into a slit provided in the core material, such as adjusting the axial force of the core material and suppressing the reduction in strength in the strong axis direction, can prevent the member from falling out or the occurrence of a region that cannot be stiffened when the core material deforms. [Means for solving the problem]

[0009] To achieve the above objective, one embodiment of the buckling-restrained brace according to the present invention is: A buckling-restrained brace having a steel plate-shaped core and a pair of restraining members made of rectangular steel pipes arranged opposite to the two wide surfaces of the core, The core material has wide sections at both ends where the width of the wide surface is relatively wide, narrow sections in the center where the width of the wide surface is relatively narrow, and transition sections connecting the wide section and the narrow section where the width of the wide surface gradually narrows toward the narrow section, and at the boundary with the narrow section the width of the wide surface is narrower than that of the narrow section. The narrow portion comprises a first narrow portion with a relatively wide surface and a second narrow portion with a relatively narrow surface, the second narrow portion serving as a shrinkage allowance during the compression deformation of the core material. The first narrow section is provided with two notches extending in the longitudinal direction of the first narrow section from the boundary with the transition section or the second narrow section on the left and right sides, and a non-notched remaining portion is provided between the ends of the two notches on the central side of the first narrow section. The present invention is characterized by having multiple of the first narrow sections.

[0010] In this embodiment, a buckling-restrained brace is provided in which two wide surfaces of a steel, plate-shaped core material are restrained by a pair of restraining members made of square steel pipes, and the core material comprises wide sections at both ends, a narrow section in the center, and a transition section connecting them. The narrow section comprises a relatively wide first narrow section and a relatively narrow second narrow section, the second narrow section becoming the shrinkage allowance during the compression deformation of the core material, and in the first narrow section, two notches are provided extending in the longitudinal direction of the first narrow section from the boundary with the transition section or the second narrow section on the left and right, and a retaining allowance is provided between the ends of the two notches on the central side of the first narrow section, so that the area on the edge side of the first narrow section beyond the two notches becomes a spacer. This spacer is the core material itself and is not inserted through a slit. A shrinkage allowance during compression deformation is secured in the transition section and the second narrow section, and the spacer is connected to other areas of the first narrow section via a retaining allowance. As a result, it is possible to adjust the axial force of the core material and suppress the reduction in strength in the strong axis direction of the core material, while eliminating problems such as spacer detachment and the occurrence of areas that cannot be stiffened due to spacer movement.

[0011] In this way, a virtual slit is formed in the first narrow section of the core material by the cut, and a virtual spacer formed by the core material itself, rather than a spacer that is manufactured separately as in the conventional method, is placed outside this virtual slit (on the pair of end sides of the wide surface of the first narrow section).

[0012] Furthermore, compared to a manufacturing method in which a slit is processed into the wide surface of the narrow section of the core material, a spacer is manufactured separately, and the spacer is inserted into the slit, this method only requires cutting into the wide surface of the first narrow section of the core material using methods such as laser processing or plasma processing, thus significantly improving manufacturing efficiency.

[0013] Since the spacer is provided in the area on the edge side of the wide surface of the first narrow section of the core material, it can be called an "external spacer," and is a different form of spacer from an "internal spacer" which is provided on the inside of the narrow section.

[0014] Here, "a plurality of first narrow sections are provided" includes, for example, a configuration having two first narrow sections and one second narrow section between them, or a configuration having three second narrow sections and two second narrow sections between them, and so on.

[0015] By providing two notches in each of the two end-side regions of the first narrow section of the core material, the width between the two end-side notches becomes the effective width in the first and second narrow sections. Because the core material has a narrow section with a relatively narrow width on the wider surface at its longitudinal center and a wide section with a relatively wide width on its longitudinal end, the narrow section at the center can be made a region that is easily plasticized. For example, this makes it possible to effectively generate higher-order mode buckling in the weak axis direction of the narrow section throughout the entire area, thereby effectively absorbing seismic energy.

[0016] Here, the plan view shape of the transition section can be described as a shape in which the width of the wide surface narrows in a curved manner from the end of the wide section to the end of the narrow section, or a shape in which the width of the wide surface narrows in a tapered manner.

[0017] Furthermore, there are two configurations between the core material and the restraining material: one in which an unbonded material is interposed, and another in which there is no unbonded material. In the configuration with an unbonded material, the unbonded material is made of an elastic material with deformability, such as butyl rubber. By interposing this unbonded material between the wide surface of the core material and the restraining material, the thickness of the unbonded material acts as a clearance, allowing higher-order mode buckling to occur within this clearance when the core material is subjected to compressive force. On the other hand, in the unbonded material-less configuration, a gap is provided between the core material and the restraining material, allowing the higher-order mode buckling of the core material to be absorbed by the gap. In addition, when the buckling-restrained brace has an unbonded material, an insert plate may be interposed between the unbonded material and the restraining material. In this configuration, by interposing, for example, a steel insert plate between the unbonded material and the restraining material, the compressive force due to buckling of higher-order modes in the weak axis direction of the core material acts directly on the restraining material, effectively suppressing local failure of the restraining material.

[0018] Furthermore, in other embodiments of the buckling-restrained brace according to the present invention, The aforementioned cut is characterized by being continuous from the boundary to the remaining portion.

[0019] According to this embodiment, the manufacturing efficiency is further improved because the cut is continuous from the boundary with the transition section and the boundary with the second narrow section to the remaining portion in the center of the first narrow section.

[0020] Furthermore, in other embodiments of the buckling-restrained brace according to the present invention, The aforementioned cuts are intermittently provided between the boundary and the remaining portion, and a separate remaining portion, different from the remaining portion located on the central side of the first narrow portion, is provided between adjacent cuts.

[0021] According to this aspect, the cuts are intermittently provided from the boundaries with the transition part and the second narrow part to the allowance remaining at the center of the first narrow part, and by providing a separate allowance between adjacent cuts, when the length of the cut is long, the workability such as laser processing may decrease, and the processing accuracy of the cut may decrease. On the other hand, good workability and ensuring the processing accuracy of the cut can be achieved.

[0022] Also, in another aspect of the buckling restraint brace according to the present invention, At both ends of the core material, a pair of joining plates that are joined to other members perpendicular to the wide surface are fixed, A reinforcing plate is fixed to the pair of joining plates, and the end portion of the restraint material is accommodated in the space formed by the wide surface, the pair of joining plates, and the reinforcing plate, On the side of the core material, a pair of supplementary stiffening members connect both sides of the pair of restraint materials, The core material is characterized by being surrounded by the pair of restraint materials and the pair of supplementary stiffening members.

[0023] According to this aspect, a pair of joining plates perpendicular to the wide surface are fixed at both ends of the core material, a reinforcing plate is fixed to the pair of joining plates, and the end portion of the restraint material is accommodated in the space formed by the wide surface, the pair of joining plates, and the reinforcing plate, thereby forming a buckling restraint brace having a high-strength end structure. Here, examples of the other members to which the joining plates are joined include connection fixtures such as brackets and gusset plates that project into the plane from the corners of the building structure. Also, when the end of the core material is used as a web, the pair of joining plates perpendicular to this web become a pair of flanges.

[0024] Also, by connecting both sides of the pair of restraint materials with a pair of supplementary stiffening members on the side of the core material, the deformation in the width direction (strong axis direction) of the core material can be restrained by the supplementary stiffening members.

Advantages of the Invention

[0025] As can be understood from the above explanation, the buckling-restrained brace of the present invention provides similar effects to the conventional structure in which a spacer is inserted into a slit provided in the core material, such as adjusting the axial force of the core material and suppressing the reduction in strength in the strong axis direction, while preventing the member from falling out or the occurrence of areas that cannot be stiffened when the core material deforms. [Brief explanation of the drawing]

[0026] [Figure 1] This is an exploded perspective view of an example of a buckling-restrained brace according to an embodiment. [Figure 2] This is a perspective view of an example of a buckling-restrained brace according to an embodiment. [Figure 3] This is a longitudinal cross-sectional view of the buckling-restrained brace according to the embodiment, in the direction perpendicular to the axis. [Figure 4] A plan view of an example of a core material. [Figure 5] This is a plan view of another example of the core material. [Figure 6A] This is a schematic longitudinal cross-sectional view of a buckling-restrained brace in the direction perpendicular to the axis, illustrating the state in which the compressive force during higher-order mode buckling acts from the core material to the restraining material. [Figure 6B] This is a schematic axial longitudinal section diagram of a buckling-restrained brace, illustrating the state in which compressive forces during higher-order mode buckling are acting from the core material to the restraining material. [Modes for carrying out the invention]

[0027] The buckling-restrained brace according to the embodiment will be described below with reference to the attached drawings. In this specification and drawings, substantially identical components may be denoted by the same reference numerals to avoid redundant explanations.

[0028] [Buckling-restrained brace according to an embodiment] An example of a buckling-restrained brace according to the embodiment will be described with reference to Figures 1 to 6. Here, Figure 1 is an exploded perspective view of an example of a buckling-restrained brace according to the embodiment, Figure 2 is a perspective view of an example of a buckling-restrained brace according to the embodiment, and Figure 3 is a longitudinal cross-sectional view of the buckling-restrained brace according to the embodiment in the direction perpendicular to the axis. Also, Figures 4 and 5 are both plan views of an example of a core material.

[0029] The buckling-restrained brace 100 comprises a core material 10, a pair of restraining members 30 arranged to face the two wide surfaces 10a of the core material 10, and an unbonded material 20 interposed between the core material 10 and the restraining members 30. In addition to the illustrated example, an insert plate made of steel plate may be interposed between the unbonded material 20 and the restraining members 30. Furthermore, there may be an unbonded material-less configuration in which the unbonded material 20 is not provided, and in this configuration, a gap approximately equal to the thickness of the unbonded material 20 is provided between the core material 10 and the restraining members 30.

[0030] The core material 10 is preferably made of steel with a low yield point, such as SN material (rolled steel for building structures) or LYP material (ultra-low yield point steel). By applying a core material 10 made of these materials, the seismic energy absorption performance due to yielding of the core material 10 is improved.

[0031] The core material 10 is formed from an elongated steel plate and has a narrow section 11 (first narrow section 11A, second narrow section 11B) at the center of its longitudinal direction where the widths t2 and t3 (see Figure 4) of the wide surface 10a are both relatively narrow, and a wide section 12 at the end of its longitudinal direction where the width t1 of the wide surface 10a is relatively wide. The core material 10 further has a transition section 13 connecting the wide section 12 and the narrow section 11, where the width of the wide surface 10a gradually narrows towards the narrow section 11, and at the boundary P2 with the first narrow section 11A, the width t3 of the wide surface is narrower than that of the first narrow section 11A.

[0032] The core material 10 has a narrow section 11 on its longitudinal central side and a wide section 12 on its longitudinal end side. This makes the narrow section 11 on the central side a region that is easily plasticized, and furthermore, the plasticization region can be limited to the narrow section 11 on the central side.

[0033] The transition section 13 in the illustrated example has a shape in which the width gradually narrows in a curved manner from the wide section 12 to the narrow section 11, thereby preventing the occurrence of localized stress concentration areas due to abrupt changes in width. Here, the transition section 13 may have a shape in which the width gradually narrows in a tapered manner, in addition to the curved shape shown in the illustrated example.

[0034] At the center of the narrow section 11 of the core material 10, cylindrical steel projections 15 protrude from the two wide surfaces 10a of the narrow section 11. The projections 15 are joined to the wide surfaces 10a of the narrow section 11 by welding or the like.

[0035] Furthermore, a pair of notches 16A and 16B extending in the longitudinal direction of the narrow portion 11 are provided in the region on the side of the pair of end edges 11a of the wide surface 10a of the first narrow portion 11 of the core material 10. Non-notched retaining areas 17 are provided between the ends of the two notches 16A, 16A and between the ends of the two notches 16B, 16B on the central side of the first narrow portion 11A, and spacers S are formed on the end sides (outside) of the notches 16A, 16B. In addition, the narrow portion 11 comprises multiple first narrow portions 11A, with second narrow portions 11B provided between adjacent first narrow portions 11A. These first narrow portions 11A, second narrow portions 11B, notches 16A, 16B, retaining areas 17, spacers S, etc. will be explained in detail below.

[0036] A pair of steel plates, forming a joining plate 14A, are joined to the wide sections 12 at both ends of the core material by welding or other means, perpendicular to the wide surface 10a and connected to other members.

[0037] The wide section 12 and the connecting plate 14A are provided with bolt holes 12a and 14a, respectively, which are aligned with the bolt holes of connecting jigs (other members) such as brackets and gusset plates that protrude into the structural plane from corners of the building frame (not shown), and are bolted together.

[0038] A reinforcing plate 14B made of steel is joined to a pair of connecting plates 14A by welding or the like, and the end of the restraint member 30 is housed in the space formed by the wide portion 12 of the core material 10, the pair of connecting plates 14A, and the reinforcing plate 14B. The reinforcing plate 14B suppresses the opening of the end of the core material 10 of the restraint member 30 in the weak axis direction, thereby suppressing a decrease in strength and damage to the end of the buckling restraint brace 100.

[0039] The unbonded material 20 is interposed between the narrow portion 11 of the core material 10 and the restraining material 30, and the thickness of the unbonded material 20 provides a clearance so that when the building frame deforms, a compressive force acts on the core material 10, causing buckling (wavy deformation) of a higher-order mode in the out-of-plane direction (weak axis direction) in the narrow portion 11.

[0040] For example, an elastic material such as butyl rubber can be used as the unbonded material 20. In addition, a projection hole 20a is provided at the center of the longitudinal direction of the unbonded material 20, into which the projection 15 of the core material 10 fits.

[0041] The restraining member 30 is formed from a rectangular steel pipe with a rectangular cross-section, and the side corresponding to the long side of the rectangle is in contact with the unbonded material 20. The side of the restraining member 30 that is in contact with the unbonded material 20 is also provided with a projection hole 30a into which the projection 15 of the core material 10 fits. In the illustrated example, each corner of the rectangular steel pipe 30 is not a right angle but forms a curved surface (R section), but each corner may be a right angle.

[0042] On the side of the core material 10, a pair of stiffeners 50 made of steel plates connect both sides (the sides corresponding to the shorter sides of the rectangle) of a pair of restraining members 30 by welding or the like, and the core material 10 is surrounded by the pair of restraining members 30 and the pair of stiffeners 50.

[0043] Next, the specific configuration of the core material will be explained with reference to Figures 4 and 5. Here, both Figures 4 and 5 are plan views of an example of the core material.

[0044] The core material 10 shown in Figure 4 has wide sections 12 at both ends where the width t1 of the wide surface 10a is relatively wide, narrow sections 11 (first narrow section 11A, second narrow section 11B) at the center where the widths t2 and t3 (t2 > t3) of the wide surface 10a are both relatively narrower than the width t1, and a transition section 13 connecting the wide section 12 and the narrow section 11 where the width t3 of the wide surface 10aa gradually narrows toward the narrow section 11, and at the boundary P2 with the narrow section 11, the width t3 of the wide surface 10a is narrower than the first narrow section 11A (its width is the same as the second narrow section 11B).

[0045] In the regions on the side of the pair of end edges 11a of the wide surface 10a of the first narrow section 11, a pair of notches 16A and a pair of notches 16B are provided, extending in the longitudinal direction of the first narrow section 11A, starting from the boundary P1 with the second narrow sections 11B on the left and right, and the boundary P2 with the transition section 13. Non-notched remnants 17 are provided between the ends of the two notches 16A, 16A and between the ends of the two notches 16B, 16B on the central side of the first narrow section 11A.

[0046] Of the longitudinal width t4 of the transition section 13, at least a portion of it is a shrinkage allowance when a compressive force N acts as an axial force on the core material 10 and it undergoes compressive deformation. Similarly, the second narrow section 11B, which has a longitudinal width t5 of the core material 10, is also a shrinkage allowance when a compressive force N acts on the core material 10 and it undergoes compressive deformation.

[0047] Both cuts 16A and 16B are continuous cuts extending from the boundary P1 and P2 between the second narrow section 11 or the transition section 13 and the first narrow section 11A to the remaining portion 17.

[0048] The region of the first narrow section 11 on the edge 11a side of the two notches 16A and 16B forms a spacer S. This spacer S is the core material 10 itself, and is not inserted as a separate member through a slit opened in the core material. Furthermore, the core material 10 has a second narrow section 11B and a transition section 13 that act as a shrinkage allowance during compression deformation. In addition, the spacer S is connected to other regions via the remaining allowance 17. As a result, both the axial force adjustment of the core material 10 and the suppression of strength reduction in the strong axis direction are achieved, without the problems of spacer detachment or movement causing areas that cannot be stiffened. In this way, a virtual slit S is formed in the first narrow portion 11A of the core material 10 by the cut 16, and a virtual spacer S formed by the core material 10 itself is provided on the outside of this virtual slit S (on the side of the pair of end edges 11a of the wide surface 10a of the first narrow portion 11A), rather than a spacer that is manufactured separately as in the conventional method.

[0049] The core material 10 in the illustrated example has three first narrow sections 11A and two second narrow sections 11B located between them, but it may also have two or four or more first narrow sections and one fewer second narrow section.

[0050] Furthermore, compared to a series of manufacturing methods in which a slit is processed into the wide surface 10a of the narrow portion 11 of the core material 10 and a separately manufactured spacer is inserted into the slit, the manufacturing efficiency of the core material 10 is significantly improved because only a cut 16 is processed into the wide surface 10a of the first narrow portion 11A of the core material 10 by laser processing or plasma processing.

[0051] Furthermore, by providing two notches 16A and 16B on the left and right sides of the central remaining allowance 17 in the regions on the two end sides 11a of the first narrow portion 11A of the core material 10, the width t3 between these two notches 16A and 16B (width of the second narrow portion 11B) becomes the effective width of the narrow portion 11, and the spacer S located on the outside suppresses buckling of higher-order modes in the strong axis direction of the narrow portion 11 of this effective width.

[0052] On the other hand, the core material 10A shown in Figure 5 differs from the core material 10 in that each of the cuts 16C, 16D is intermittently provided between the boundaries P1, P2 and the remaining portion 17, and a separate remaining portion 17a, different from the remaining portion 17 located on the central side of the first narrow section 11, is provided between adjacent cuts 16C, 16C and cuts 16D, 16D.

[0053] With core material 10A, when the length of a continuous cut becomes long, the processability such as laser processing decreases, and the processing accuracy of the cut may decrease. However, since the cuts 16C and 16D are provided intermittently, it is possible to ensure good processability and processing accuracy of the cut.

[0054] Next, with reference to Figures 6A and 6B, we will explain the buckling of higher-order modes occurring in the weak axis direction of the core material 10. Here, Figures 6A and 6B are schematic longitudinal cross-sectional diagrams in the direction perpendicular to the axis and in the axial direction of the buckling-restrained brace, respectively, illustrating the state in which the compressive force during higher-order mode buckling acts from the core material to the restraining material.

[0055] The buckling-restrained brace 100 is incorporated into the building frame by bolting its ends to connecting fixtures provided at corners or other locations within the building frame. When the building frame deforms during an earthquake, external forces such as horizontal forces during the earthquake enter the ends of the buckling-restrained brace 100 via the connecting fixtures. These external forces are transmitted as a compressive force N from the ends of the core material 10 to its entire surface, causing the entire core material 10 to undergo plastic deformation, thereby exhibiting its energy absorption performance during earthquakes. In other words, when a compressive force N acts on the core material 10, higher-order mode buckling (wave-like deformation) occurs in the weak axis direction throughout the entire narrow section 11 of the core material 10. This causes the entire narrow section 11 of the core material 10 to buckle as uniformly as possible, thereby enabling the buckling-restrained brace 100 to exhibit its overall plastic deformation performance.

[0056] As shown in Figures 6A and 6B, the compressive force N acting on the core material 10 causes buckling of higher-order modes, and the peaks of the wave-like deformation due to buckling come into contact with the restraining member 30, applying a pressing force Q to the restraining member 30. Therefore, the local yield strength of the restraining member 30 is set so that local failure does not occur in response to the locally acting pressing force Q.

[0057] Furthermore, other embodiments may be used in which other components are combined with the configurations listed in the above embodiments, and the present invention is not limited in any way to the configurations shown herein. In this regard, modifications can be made without departing from the spirit of the present invention, and can be appropriately determined according to the application form. [Explanation of symbols]

[0058] 10,10A: Core material 10a: Wide surface 11: Narrow section 11A: 1st narrow part 11B: 2nd narrow width part 12: Wide section 12a: Bolt hole 13: Transition zone (shrunk area) 14A: Joint plate 14a: Bolt hole 14B: Reinforcement plate 15: Protrusion 16, 16A, 16B, 16C, 16D: Notches 17: Remainder 17a: Additional remaining charge 20: Unbonded material 20a:Protrusion hole 30: Retaining material (square steel pipe) 30a:Protrusion hole 50: Stiffener 100: Buckling-restrained brace S: Spacer (virtual spacer) N: Axial force (compressive force) Q: Pressing force P: Starting point

Claims

1. A buckling-restrained brace having a steel plate-shaped core and a pair of restraining members made of rectangular steel pipes arranged opposite to the two wide surfaces of the core, The core material has wide sections at both ends where the width of the wide surface is relatively wide, narrow sections in the center where the width of the wide surface is relatively narrow, and transition sections connecting the wide section and the narrow section where the width of the wide surface gradually narrows toward the narrow section, and at the boundary with the narrow section the width of the wide surface is narrower than that of the narrow section. The narrow portion comprises a first narrow portion with a relatively wide surface and a second narrow portion with a relatively narrow surface, the second narrow portion serving as a shrinkage allowance during the compression deformation of the core material. The first narrow section is provided with two notches extending in the longitudinal direction of the first narrow section from the boundary with the transition section or the second narrow section on the left and right sides, and a non-notched remaining portion is provided between the ends of the two notches on the central side of the first narrow section. A buckling-restrained brace characterized by having multiple of the first narrow sections.

2. The buckling-restrained brace according to claim 1, characterized in that the notch is continuous from the boundary to the remaining portion.

3. The buckling-restrained brace according to claim 1, characterized in that the notches are intermittently provided between the boundary and the remaining portion, and a separate remaining portion different from the remaining portion located on the central side of the first narrow portion is provided between adjacent notches.

4. A pair of connecting plates are fixed to both ends of the core material, perpendicular to the wide surface and joined to other members. A reinforcing plate is fixed to the pair of joining plates, and the end of the restraining member is housed in the space formed by the wide surface, the pair of joining plates, and the reinforcing plate. On the side of the core material, a pair of stiffening members connect both sides of the pair of restraining members. The buckling-restrained brace according to any one of claims 1 to 3, characterized in that the core material is surrounded by the pair of restraining members and the pair of stiffening members.

Images