Buckling-restrained brace

Abstract

The present invention relates to a buckling-restrained brace having a core material equipped with protrusions for preventing shearing, and aims to provide a buckling-restrained brace that can overcome the challenges of attaching the protrusions to the core material by welding, and that allows for easy setting of the length, shape, and strength of the protrusions. [Solution] The core material 10 is made of a steel plate, and a pair of steel restraining members 30 are arranged to face a pair of wide surfaces 11 of the core material 10. A pair of stiffening members 40 are joined to both sides of the pair of restraining members 30 on the side of the core material 10 and extend in the longitudinal direction of the core material 10. A projection 14 that protrudes toward the stiffening member is provided on at least one of the pair of narrow surfaces 12 of the core material 10 as an integrally molded member of the core material 10, and the projection 14 fits into a groove 45 provided on at least one of the pair of stiffening members 40.

Description

Technical Field

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

Background Art

[0002] Conventionally, as braces for forming building structures (column-beam structures, roof structures, etc.), buckling restraint braces with buckling prevention measures have been applied. As buckling restraint braces, there are various bracing forms, such as a form in which only steel plates reinforce around a steel core material, a form in which a steel core material is reinforced with RC (Reinforced Concrete), and a form in which a steel core material is coated with steel and mortar.

[0003] For the core material constituting the buckling restraint brace, in addition to applying a steel plate with a constant width in the longitudinal direction, there is also a case where a steel plate with a constricted shape having a narrow-width portion on the central side that becomes a plasticized portion for absorbing seismic energy and wide-width portions at both ends of the narrow-width portion is applied.

[0004] Here, Patent Document 1 proposes a buckling restraint brace provided with a core material in the latter form. The core material of the buckling restraint brace described in Patent Document 1 is further provided with an intermediate slit for yield strength adjustment, and an internal deformation prevention material made of steel material serving as a spacer is inserted into the intermediate slit so as to be relatively movable in the longitudinal direction. Here, a displacement prevention protrusion is provided on the wide-width surface of the core material, holes are formed in a pair of square steel pipes that sandwich the wide-width surface of the core material, and the displacement prevention protrusion is inserted into the holes, whereby the core material and the pair of restraint materials are assembled.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the buckling-restrained brace described in Patent Document 1, welding is used to attach the anti-slip projections to the wide surface of the core material. This requires careful welding to avoid cross-sectional defects due to undercuts, which presents challenges such as increased processing time.

[0007] Furthermore, in order to enable the insertion of the anti-slip projection into the hole, the length of the anti-slip projection needs to be as short as possible. However, the anti-slip projection is required to have the length and strength to withstand the impacts that may occur during transportation and construction and not come out of the hole. Therefore, setting the length, shape, and strength is not easy.

[0008] The present invention has been made in view of the above problems, and relates to a buckling-restrained brace having a core material equipped with protrusions for preventing shearing, with the aim of providing a buckling-restrained brace that can solve the problems of attaching the protrusions to the core material by welding and allows for easy setting of the length and shape of the protrusions. [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 core made of steel plate, A pair of steel restraining members are arranged to face the pair of wide surfaces of the aforementioned core material, The core material has a pair of stiffening members that are joined to both sides of the pair of restraining members and extend in the longitudinal direction of the core material, At least one of the pair of narrow surfaces of the core material is provided with a projection that extends toward the stiffening material, as an integrally molded member of the core material. The projection is characterized in that it fits into a groove provided in at least one of the pair of stiffening members.

[0010] According to this embodiment, a projection extending toward the stiffener is provided as an integrally molded member of the core material on at least one of the pair of narrow surfaces of the core material, thereby eliminating the need to attach the projection to the core material by welding and resolving the problems associated with welding. Furthermore, since the projection of the core material fits into a groove of the stiffener that is joined to the restraining material, rather than into a restraining material that sandwiches the wide surface of the core material, it is sufficient to provide a projection of an appropriate length and shape that fits into the groove, and the length and shape of the projection can be easily determined.

[0011] Here, the projection may be provided on only one of a pair of narrow surfaces of the core material, with a groove provided in the stiffener corresponding to the projection, or the projection may be provided on both of the pair of narrow surfaces of the core material, with grooves provided in both of the stiffeners. Furthermore, the projection may be provided at the center of the longitudinal direction of the core material, or at a position offset from the center, and may be provided as one or multiple projections on the narrow surface of the core material. In any of these configurations, a groove is provided in the stiffener at the corresponding position in the stiffener into which the projection fits. Here, the groove may be a hole that penetrates the stiffener, or a recess that does not penetrate the stiffener.

[0012] For example, when manufacturing a core material from a steel plate using a cutting process such as laser processing, a core material with a protrusion that extends laterally at a predetermined position on at least one of a pair of narrow surfaces can be manufactured by cutting the material.

[0013] Furthermore, the core material to be applied may be formed from a steel plate with a constant width in the longitudinal direction, or it may be formed from a constricted steel plate having a narrow section in the center and wider sections at both ends of the narrow section.

[0014] Furthermore, other embodiments of the buckling-restrained brace according to the present invention include: A core made of steel plate, A pair of steel restraining members are arranged to face the pair of wide surfaces of the aforementioned core material, The core material has a pair of stiffening members that are joined to both sides of the pair of restraining members and extend in the longitudinal direction of the core material, At least one of the pair of narrow surfaces of the core material is provided with a projection that extends toward the stiffening material, as an integrally molded member of the core material. At least one of the pair of stiffeners is formed from a plurality of segmented stiffeners, and the projection is sandwiched between the plurality of segmented stiffeners.

[0015] According to this embodiment, the stiffener corresponding to the projection protruding from the narrow surface of the core material is formed by multiple (for example, two) segmented stiffeners, and since the projection is sandwiched between multiple segmented stiffeners, the need to attach the projection to the core material by welding is eliminated, thereby resolving the problems associated with welding. Furthermore, since the projection is sandwiched between multiple segmented stiffeners instead of being fitted into a groove, it becomes unnecessary to set the length of the projection to a length that can be fitted into a groove, making it even easier to set the length and shape of the projection.

[0016] For example, in a configuration where protrusions extend from both of a pair of narrow surfaces of the core material, both of the pair of stiffeners are formed from multiple segmented stiffeners.

[0017] Furthermore, other embodiments of the buckling-restrained brace according to the present invention include: The core material is characterized in that reinforcing fins are welded to the two wide surfaces of the core material, extending from each end over a predetermined range in the longitudinal direction of the core material, in a direction perpendicular to the wide surfaces.

[0018] According to this embodiment, reinforcing fins are provided on the two wide surfaces of the core material, extending from each end to a predetermined range in the longitudinal direction of the core material, thereby effectively reinforcing the end of the core material that is joined to the bracket of the frame, etc. Here, an end plate extending in a direction perpendicular to the longitudinal direction is welded to the longitudinal end of the core material, and the bracket of the frame and the end plate can be bolted to each other.

[0019] Also, another aspect of the buckling restraint brace according to the present invention is that at a position corresponding to the core material of the supplementary rigid material, a first slit is provided over a predetermined range in the longitudinal direction from the end of the supplementary rigid material, and a closing plate for closing the first slit is attached to the outer surface of the supplementary rigid material, and a first gap is provided between the narrow-width surface of the core material and the inner surface of the closing plate.

[0020] According to this aspect, since a first slit is provided at a position corresponding to the core material of the supplementary rigid material, a closing plate for closing the first slit is attached to the outer surface of the supplementary rigid material, and a first gap is provided between the narrow-width surface of the core material and the inner surface of the closing plate, interference between the core material and the supplementary rigid material can be suppressed by the first gap.

[0021] Here, "a first slit is provided over a predetermined range in the longitudinal direction from the end of the supplementary rigid material" means, for example, setting a predetermined range as the range in which the deformed core material can contact the supplementary rigid material based on the deformation mode in the cross-sectional plane at the end of the core material during a major earthquake, and providing the first slit within this range.

[0022] Also, another aspect of the buckling restraint brace according to the present invention is that at a position corresponding to the core material of the supplementary rigid material, a convex portion protruding outward is provided over a predetermined range in the longitudinal direction from the end of the supplementary rigid material, and a first gap is provided between the narrow-width surface of the core material and the inner surface of the convex portion.

[0023] According to this aspect, since a convex portion protruding outward is provided at a position corresponding to the core material of the supplementary rigid material, and the first gap as described above is provided between the narrow-width surface of the core material and the inner surface of the convex portion, interference between the core material and the supplementary rigid material can be suppressed by the first gap.

[0024] Also, another aspect of the buckling restraint brace according to the present invention is that The restraining member is characterized in that a second slit is provided at a position corresponding to the reinforcing fin, with a second gap between it and the reinforcing fin, in order to prevent interference with the reinforcing fin.

[0025] According to this embodiment, a second slit is provided in the restraining member at a position corresponding to the reinforcing fin, with a second gap between the slit and the reinforcing fin, thereby effectively preventing interference between the reinforcing fin and the end region of the restraining member when the reinforcing fin is long and interference between the reinforcing fin and the end region of the restraining member is possible. Here, the second gap between the reinforcing fin and the end face of the second slit is set to a width such that the reinforcing fin and the second slit do not come into contact when the core material deforms, for example, during a major earthquake. [Effects of the Invention]

[0026] As can be understood from the above explanation, the buckling-restrained brace of the present invention relates to a buckling-restrained brace having a core material equipped with protrusions for preventing shearing, and it is possible to solve the problems that arise when attaching the protrusions to the core material by welding, and the length and shape of the protrusions can be easily set. [Brief explanation of the drawing]

[0027] [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 view along the line III-III in Figure 2. [Figure 4] This is a view from arrow IV-IV in Figure 2. [Figure 5] This is an exploded perspective view of another example of a buckling-restrained brace according to the embodiment. [Figure 6] This is a perspective view of yet another example of a buckling-restrained brace according to the embodiment. [Figure 7] This is a view along the line VII-VII in Figure 6. [Modes for carrying out the invention]

[0028] 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.

[0029] [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 7. Here, Figure 1 is an exploded perspective view of an example of a buckling-restrained brace according to the embodiment, and Figure 2 is a perspective view of an example of a buckling-restrained brace according to the embodiment. Figures 3 and 4 are views taken along the lines III-III and IV-IV in Figure 2, respectively. Furthermore, Figure 5 is an exploded perspective view of another example of a buckling-restrained brace according to the embodiment, Figure 6 is a perspective view of yet another example of a buckling-restrained brace according to the embodiment, and Figure 7 is a view taken along the line VII-VII in Figure 6.

[0030] As shown in Figure 1, the buckling-restrained brace 100 comprises a core material 10, a pair of steel restraint members 30 arranged opposite to the two wide surfaces 11 of the core material 10, and a pair of stiffeners 40 extending longitudinally and welded to the upper and lower side surfaces 32 of the pair of restraint members 30 on the side of the core material 10. Here, although not shown in the figure, the core material may have a slit and a separate internal spacer may be slidably disposed within the slit, or a pair of external spacers may be disposed between the pair of narrow surfaces 12 of the core material 10 and the pair of stiffeners 40.

[0031] Furthermore, the core material 10 in the illustrated example is provided with projections 14 that protrude outward in the central region (approximately the central region) in the longitudinal direction of each of the pair of narrow surfaces 12. The core material 10 is formed by cutting a steel plate, and the entire core material 10, including the projections 14, is manufactured during this cutting process. Therefore, the projections 14 are integrally molded members of the core material 10.

[0032] 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.

[0033] The core material 10 in the illustrated example has a slender rectangle in plan view, where the width of its wide surface 11 is the same throughout its entire length. However, it may also have a constricted shape with a narrow section in the center and wide sections at both ends.

[0034] At the center of the widthwise direction of the two wide surfaces 11 of the core material 10, reinforcing fins 15 made of steel plates are welded in a direction perpendicular to the wide surfaces 11, extending from the longitudinal ends 13 of each surface to a predetermined range L1 in the longitudinal direction of the core material 10. In the illustrated example, the reinforcing fins 15 have a plan view shape in which the width changes in a stepped manner midway, but they may also have a form with a constant width or a form in which the width changes in two or more steps.

[0035] Reinforcement fins 15 are provided on the two wide surfaces 11 of the end 13 of the core material 10, making the end cross-shaped, thereby ensuring the rigidity of the longitudinal end of the core material 10 (especially the rigidity in the weak axis direction). Therefore, the length of the reinforcement fins 15 (a predetermined range L1) is set to a length that provides the required strength (bending rigidity and shear rigidity) to withstand the sectional forces generated at the end of the core material 10 when the core material 10 deforms during a major earthquake.

[0036] An end plate 17 is welded to the longitudinal end 13 of the core material 10 shown in Figure 1. Here, "welding" in this specification refers to a type of welding that is appropriate for the strength required at the joint and the type of joint, such as groove welding (full penetration welding, partial penetration welding), fillet welding, or laser welding.

[0037] In fabricating the buckling-restrained brace, a steel end plate 17 extending perpendicular to the longitudinal direction is welded to the longitudinal end 13 of the core material 10. The end plate 17 has multiple (two in the illustrated example) bolt holes 17a through which bolts are inserted when the buckling-restrained brace is bolted to a bracket (not shown) attached to the side of a column forming the building frame when the buckling-restrained brace is incorporated into a building frame (not shown).

[0038] The restraining member 30 is formed from a rectangular steel pipe with a rectangular cross-section. Here, the restraining member may be formed from anything other than a rectangular steel pipe, such as channel steel or a shaped steel unit formed by assembling two angle steels into a rectangular frame.

[0039] In the restraining member 30, a second slit 33 is provided in a position corresponding to the reinforcing fin 15 attached to the core material 10, extending from the end 34 to a predetermined length L2 to prevent interference with the reinforcing fin 15 when assembling the restraining member 30.

[0040] Furthermore, as shown in Figure 2, a second gap G2 of a predetermined width is provided between the second slit 33 and the end face of the reinforcing fin 15.

[0041] The width of this second gap G2 is set such that, for example, when the core material 10 deforms in the strong axis direction during a major earthquake, the reinforcing fins 15 and the end face of the second slit 33 do not come into contact. This prevents the reinforcing fins 15 from pressing against the end face of the second slit 33 and damaging the end of the restraining member 30 during a major earthquake.

[0042] Furthermore, a fourth gap (not shown) is provided between the tip of the reinforcing fin 15 and the end of the second slit 33. The length L2 of the second slit 33 is set such that, for example, when the core material 10 is compressed and shrinks longitudinally due to a major earthquake, the tip of the reinforcing fin 15 does not come into contact with the second slit 33. This fourth gap also prevents the reinforcing fin 15 from pressing against the end face of the second slit 33 and damaging the end of the restraining member 30 during a major earthquake.

[0043] On each of the opposing surfaces 41 of the pair of stiffeners 40, grooves 45 are provided in the X1 direction, as shown in Figure 1, at positions corresponding to the projections 14 provided on the narrow surface 12 of the core material 10, into which the projections 14 fit. By fitting the projections 14 into each groove 45, displacement of the assembled core material 10 can be prevented.

[0044] The groove 45 does not penetrate the stiffener 40, and therefore, when the stiffener 40 is assembled and the buckling-restrained brace 100 is manufactured, the projection 14 fitted into the groove 45 is not visible from the outside, and the aesthetic appearance of the buckling-restrained brace 100 is not impaired. However, if there is no problem with the aesthetic appearance, the groove may be a through-hole that penetrates the stiffener 40.

[0045] In this way, since the projection 14 that protrudes toward the stiffening member is provided as an integrally molded member of the core material 10, it is possible to eliminate problems such as increased processing time, which arises when the projection is attached to the core material by welding, for example, due to the need to carefully weld in order to avoid cross-sectional defects caused by undercuts.

[0046] Furthermore, since the projections 14 of the core material 10 fit into grooves 45 of the stiffening material 40 joined to the restraining material 30, rather than into the restraining material 30 that sandwiches the wide surface 11 of the core material 10, it is sufficient to provide the core material 10 with projections 14 of an appropriate length that fit into the grooves 45, and the length and shape of the projections 14 can be easily determined.

[0047] In this illustrated example, projections 14 are provided at approximately the center of the longitudinal direction on each of the pair of narrow surfaces 12 of the core material 10, and grooves 45 are provided on the pair of stiffeners 40 at positions corresponding to each projection 14. However, other configurations are also possible. That is, projections 14 may be provided on only one of the pair of narrow surfaces 12, or projections 14 may be provided at one or more positions other than the center of the longitudinal direction on the narrow surfaces 12. In any of these configurations, grooves 45 are provided on the stiffeners 40 at positions corresponding to the projections 14.

[0048] Figure 3 is a longitudinal cross-sectional view taken at the position of the projection 14 of the core material 10, with the cross-section perpendicular to the longitudinal direction. As shown in the figure, when the projection 14 of the core material 10 is fitted into the groove 45 of the stiffener 40 and displacement of the core material 10 is prevented, a third gap G3 with length (width) L3 is provided between the wide surface 11 of the core material 10 and the opposing surface 31 of the restraining material 30.

[0049] The length (width) L3 of the third gap G3 provided between the opposing surface 31 of the restraining member 30 and the wide surface 11 of the core material 10 is set to a width that prevents buckling of the core material 10 in the weak axis direction during a major earthquake, prevents suppression of deformation of the core material 10 in the weak axis direction during a major earthquake, and effectively absorbs earthquake energy.

[0050] Figure 4 is a longitudinal cross-sectional view of the core material 10, cut in a section perpendicular to the longitudinal direction at the general part (the part without the protrusions 14). A first gap G1 with length (width) L4 is provided between the inner surface 41 of the stiffener 40 and the narrow surface 12 of the core material 10. This first gap G1 suppresses interference between the narrow surface 12 of the core material 10 and the inner surface 41 of the stiffener 40 when relative displacement occurs between the core material 10 and the stiffener 40 during a major earthquake.

[0051] Unlike the buckling-restrained brace 100 shown in Figure 5, which has a stiffener 40 with a groove 45 into which the projection 14 of the core material 10 fits, the buckling-restrained brace 100A has a stiffener 40A formed by two divided stiffeners 47 that sandwich the projection 14 arranged in the X2 direction and prevent the core material 10 from shifting.

[0052] In the case of the stiffening material 40A, it is sufficient to manufacture a flat, rectangular parallelepiped-shaped segmented stiffening material 47, which eliminates the need to process the groove 45, thus improving the ease of manufacturing the stiffening material.

[0053] In addition, even in this embodiment, the core material 10 may have a projection 14 on only one narrow surface 12. In this case, the stiffener corresponding to the projection 14 may be formed by two divided stiffeners 47, and the other stiffener may be a single stiffener without a groove 45.

[0054] Furthermore, the buckling-restrained brace 100B shown in Figures 6 and 7 differs from the buckling-restrained braces 100 and 100A in that a first slit 48 is provided from the end of the stiffener 40B over a predetermined range in the longitudinal direction, at a position corresponding to the narrow surface 12 of the core material 10 of the stiffener 40B, and a closing plate 49 that closes the first slit 48 is attached to the outer surface 42 of the stiffener 40B. In other words, the buckling-restrained brace 100B, like the other buckling-restrained braces 100 and 100A, has a core material 10 equipped with a projection 14 which is an integrally molded member, and the stiffener 40B is equipped with a groove 45 into which the projection 14 fits, or is formed of a segmented stiffener in which the projection 14 is sandwiched.

[0055] A first gap G4 with length (width) L5 is provided between the narrow surface 12 of the core material 10 and the inner surface 49a of the closing plate 49. As is clear when compared with the first gap G1 with length (width) L4 shown in Figure 4, a larger gap can be provided between the narrow surface 12 of the core material 10 and the stiffener 40B (and the closing plate 49 joined to it). Therefore, when relative displacement occurs between the core material 10 and the stiffener 40B during a major earthquake, interference between the narrow surface 12 of the core material 10 and the closing plate 49 located outside the first slit 48 of the stiffener 40B can be suppressed by the first gap G4.

[0056] Here, although not shown in the diagram, in addition to the configuration in which a first slit is provided in the stiffener and a closing plate that closes the first slit is attached to the outside, there may also be a configuration in which a protrusion is provided in the stiffener at a position corresponding to the core material, extending outward from the end of the stiffener over a predetermined range in the longitudinal direction, and a first gap is provided between the narrow surface 12 of the core material 10 and the inner surface of the protrusion.

[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: Core material 11: Wide surface 12: Narrow surface 13: End 14: Protrusion 15: Reinforcement fins 17: End plate 17a: Bolt hole 30: Retaining material (square steel pipe) 31: Opposing surface 32: Side view 33: Second Slit 34: End 40,40A,40B: Stiffener 41: Inner surface (opposite surface) 42:Outer surface 45: Groove 47: Split stiffener 48: First Slit 49: Occlusion plate 49a:Inner surface 100, 100A, 100B: Buckling-restrained brace G1, G4: First gap G2: Second gap G3: Third gap

Claims

1. A core made of steel plate, A pair of steel restraining members are arranged to face the pair of wide surfaces of the aforementioned core material, The core material has a pair of stiffening members that are joined to both sides of the pair of restraining members and extend in the longitudinal direction of the core material, At least one of the pair of narrow surfaces of the core material is provided with a projection that extends toward the stiffening material, as an integrally molded member of the core material. A buckling-restrained brace characterized in that the projection is fitted into a groove provided in at least one of the pair of stiffeners.

2. A core made of steel plate, A pair of steel restraining members are arranged to face the pair of wide surfaces of the aforementioned core material, The core material has a pair of stiffening members that are joined to both sides of the pair of restraining members and extend in the longitudinal direction of the core material, At least one of the pair of narrow surfaces of the core material is provided with a projection that extends toward the stiffening material, as an integrally molded member of the core material. A buckling-restrained brace characterized in that at least one of the pair of stiffeners is formed from a plurality of segmented stiffeners, and the projection is sandwiched between the plurality of segmented stiffeners.

3. The buckling-restrained brace according to claim 1 or 2, characterized in that reinforcing fins are welded to the two wide surfaces of the core material, extending from each end over a predetermined range in the longitudinal direction of the core material in a direction perpendicular to the wide surfaces.

4. A first slit is provided in the stiffener at a position corresponding to the core material, extending from the end of the stiffener over a predetermined range in its longitudinal direction, and a closing plate is attached to the outer surface of the stiffener to close the first slit. The buckling-restrained brace according to claim 1 or 2, characterized in that a first gap is provided between the narrow surface of the core material and the inner surface of the closing plate.

5. At a position corresponding to the core material of the stiffening material, a protrusion is provided that extends outward from the end of the stiffening material over a predetermined range in its longitudinal direction. The buckling-restrained brace according to claim 1 or 2, characterized in that a first gap is provided between the narrow surface of the core material and the inner surface of the protrusion.

6. The buckling-restrained brace according to claim 3, characterized in that, among the restraining members, a second slit is provided at a position corresponding to the reinforcing fin, with a second gap between it and the reinforcing fin to prevent interference with the reinforcing fin.

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