JP2024044766A - buckling restraint brace - Google Patents

Abstract

[Problem] To provide a buckling restrained brace that ensures sufficient rigidity in the end regions in the longitudinal direction while reducing the number of parts in the end regions, making it easy to handle and easy to manufacture. [Solution] A buckling restrained brace 100 has a core material 10 whose wide faces 11 have the same width over the entire area, a pair of restraining members 30 made of square steel pipes arranged to face the two wide faces 11 of the core material 10, end plates 17 welded to the longitudinal ends 12 of the core material 10, and a pair of stiffeners 50 welded to both side faces 31 of the pair of restraining members 30, with reinforcing fins 15 welded to the two wide faces 11 from the respective ends 12 over a predetermined longitudinal range t2, protrusions 52 projecting outward from the ends 51 of the stiffeners 50 over a predetermined longitudinal range t4, and a gap G between the core material 10 and the inner side of the protrusions 52. [Selected Figure] Figure 4

Description

The present invention relates to buckling restraint braces.

BACKGROUND ART Conventionally, buckling restraint braces with buckling prevention measures have been used as braces forming building frames (column/beam frames, roof frames, etc.). Buckling restraint braces are available in a form in which the periphery of a steel core material is reinforced with only a steel plate, a form in which the periphery of a steel core material is reinforced with RC (Reinforced Concrete), and a form in which the periphery of a steel core material is reinforced with RC (Reinforced Concrete). There are various types of reinforcement, including one in which the surrounding area is covered with steel and mortar.

Here, Patent Document 1 relates to a buckling restraint brace in which the core material is restrained by a restraining material formed of a pair of square steel pipes, and a buckling restraint brace that does not cause local fracture in the restraining material subjected to pressing force from the core material. Flexible restraint braces have been proposed. Specifically, a core material having a joint part for joining with other members at both ends of the plate-like part, and a restraining material arranged opposite to each surface perpendicular to the weak axis direction of the plate-like part. It is a buckling restraint brace with.

In this buckling restraint brace, a pair of flanges are welded to both ends of the plate portion in the width direction at the end of the core material, and a pair of reinforcing plates are welded to both ends of the pair of flanges. The ends of the restraining materials are placed in the two spaces surrounded by the plate-shaped part, the pair of flanges, and the reinforcing plate, and the pair of stiffening materials are welded to the sides of the pair of restraining materials. has been done. Here, the width of the wide surface of the core material is relatively wider in the end regions than in the center region, and the core material is formed by constricting the transition region connecting the center region and the end regions.

Patent No. 6445862

According to the buckling restraint brace described in Patent Document 1, members such as ready-made square steel pipes can be easily used as restraint members, and the restraints subjected to pressing force from the core material can be easily used without increasing costs. It becomes possible to suppress local destruction of the material.

By the way, when the buckling restraint brace described in Patent Document 1 is incorporated into a building frame, the buckling restraint is applied to two brackets etc. attached to the inner side surfaces of a pair of columns that constitute the building frame. The longitudinal ends of the brace are bolted together. Patent Document 1 does not mention an end plate provided at the longitudinal end of the core material, but when the ends of the buckling restraint brace are bolted to two brackets in this way, the core material An end plate with bolt holes is welded to the longitudinal end of the material, and the end plate and the bracket are bolted together. In addition, the core material has a wide part located at both ends in the longitudinal direction and whose wide side is relatively wide, and a narrow part located at the center where the width of the wide side is relatively narrow. The end plate is welded to the longitudinal end of this wide portion.

In the longitudinal end region of the buckling restraint brace described in Patent Document 1, when the above-mentioned end plate is further included, the end plate is welded to the wide part of the core material, and a pair of flanges (joining plates). Since there are a total of five members to be welded, such as a pair of reinforcing plates, the number of parts is large and the maneuverability of the buckling restraint brace may be reduced. A buckling restraint brace that has a small number of parts and is easy to handle is desired. Furthermore, since the core material described in Patent Document 1 has a constricted transition region connecting the central region and the end regions, the constricted shape is processed by laser processing etc. Manufacturing yields are reduced, which can lead to reduced manufacturability of the buckling restraint brace.

The present invention has been made in view of the above-mentioned problems, and while ensuring sufficient rigidity in the longitudinal end region of a buckling restraint brace, the number of parts in the end region is reduced and maneuverability is improved. The purpose is to provide a buckling restraint brace with good manufacturability.

In order to achieve the above object, one aspect of the buckling restraint brace according to the present invention is to
A core material made of a steel plate, the width of the wide surface being the same throughout;
A pair of restraining members made of square steel pipes arranged to face the two wide surfaces of the core material;
an end plate welded to an end of the core material in a longitudinal direction and extending in a direction perpendicular to the longitudinal direction;
a pair of stiffeners welded to both side surfaces of the pair of restraint members on the sides of the core member;
A reinforcing fin is welded to each of the two wide surfaces of the core material so as to extend in a direction perpendicular to the wide surfaces from each end over a predetermined range in the longitudinal direction of the core material,
The stiffener has a protruding portion that protrudes outward from the end of the stiffener over a predetermined range in the longitudinal direction at a position of the stiffener corresponding to the core material, and a gap is provided between the core material and the inner surface of the protruding portion.

According to this aspect, by applying a core material whose wide side width is the same throughout the entire area, there is no need to process the constriction shape by laser processing, etc., so the production yield of the core material is improved, and the seat Manufacturability of the bending restraint brace can be improved. In addition, reinforcing fins are provided on the two wide sides of the core material from each end to a predetermined range in the longitudinal direction of the core material, and flanges and reinforcing plates in the end regions are eliminated. The number of parts in the end region is reduced, resulting in a buckling restraint brace with good maneuverability.

Furthermore, regarding a pair of stiffeners that are welded to both sides of a pair of restraint members on the sides of the core member, at a position corresponding to the core member, the outer side extends over a predetermined range in the longitudinal direction from the end of the stiffener member. Because a protrusion is provided that protrudes out, and a gap is provided between the core material and the inner surface of the protrusion, the building frame deforms in the event of a major earthquake, and the wide surface of the core material When the core material of the buckling restraint brace, which is incorporated so that it is parallel to the structural surface, deforms within the structural surface, the interference between the core material and the stiffening material is prevented by the gap inside the convex part. This can prevent the core material from pressing against the stiffener and damaging the stiffener.

Here, the phrase "the reinforcing fins extend over a predetermined range in the longitudinal direction of the core material from the end of the core material" means, for example, that the reinforcing fins are set within a predetermined range that can ensure the rigidity of the end of the core material in the event of a major earthquake. This means that reinforcing fins are provided in this range. Furthermore, "a convex portion extending outward over a predetermined range in the longitudinal direction from the end of the stiffener is provided" means, for example, deformation within the structural plane of the end of the core material during a major earthquake. This means that the range in which the deformed core material can come into contact with the stiffening material is set to a predetermined range based on the mode, and the convex portion is provided in this range.

There are two types: one in which an unbond material is present between the core material and the restraint material, and the other in which an unbond material is not present. In the case where an unbond material is present, the unbond material is formed of an elastic material having deformability such as butyl rubber. Because this unbonded material is interposed between the wide surface of the core material and the restraining material, higher-order mode buckling occurs within this clearance when the core material is subjected to compressive force using the thickness of the unbonded material as a clearance. It becomes possible to do so. On the other hand, in the unbonded material-less configuration, a gap is provided between the core material and the restraint material, and it becomes possible to absorb higher-order mode buckling of the core material in the gap.

Here, when the buckling restraint brace has an unbonded material, an insert plate may be interposed between the unbonded material and the restraining material. In this configuration, by interposing an insert plate, for example made of steel, between the unbonded material and the restraining material, the pressing force due to higher-order mode buckling in the weak axis direction of the core material acts directly on the restraining material, effectively preventing localized failure of the restraining material.

Further, other aspects of the buckling restraint brace according to the present invention include:
A core material made of a steel plate material, the width of the wide side being the same throughout the entire area;
a pair of restraining members made of square steel pipes, arranged so as to face the two wide surfaces of the core material;
an end plate welded to the longitudinal end of the core material and extending in a direction perpendicular to the longitudinal direction;
a pair of stiffeners welded to both sides of the pair of restraint members on the sides of the core material,
Reinforcing fins are provided on 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,
A first slit is provided at a position of the stiffening material corresponding to the core material, extending from an end of the stiffening material to a predetermined range in the longitudinal direction, and a cover material surrounding the first slit is provided with a first slit in a position corresponding to the core material. The core material is joined to the outer surface of the rigid material, and a gap is provided between the core material, the inner surface of the cover material, and the first slit.

According to this aspect, a pair of stiffeners welded to both sides of a pair of restraining members on the side of the core member have a first slit at a position corresponding to the core member over a predetermined range in the longitudinal direction from the end of the core member, a cover material surrounding the first slit is joined to the outer surface of the stiffener member, and a gap is provided between the core member, the inner surface of the cover material, and the first slit. When the building frame is deformed during a large earthquake and the core member of the buckling restraint brace, which is incorporated so that the wide surface of the core member is parallel to the structural surface of the building frame, is deformed within the structural surface, interference between the core member and the stiffener member is absorbed by the first slit provided in the stiffener member and the inner gap of the cover material surrounding it, and the core member can be prevented from pressing the stiffener member and damaging the stiffener member. In other words, in this aspect, instead of a form in which a protrusion is provided in the stiffener member as an interference prevention mechanism between the deformed core member and the stiffener member, a first slit is provided in the stiffener member and this first slit is surrounded by the cover material.

Further, other aspects of the buckling restraint brace according to the present invention include:
A second slit for preventing interference with the reinforcing fin is provided at a position corresponding to the reinforcing fin in the restraining material, with a gap provided between the second slit and the reinforcing fin. shall be.

According to this aspect, the second slit that prevents interference with the reinforcing fin is provided at a position corresponding to the reinforcing fin in the restraining material, with a gap provided between the second slit and the reinforcing fin. In the case where the length of the fin is long and the reinforcing fin and the end region of the restraint material may interfere with each other, interference between the two is effectively prevented. Here, the gap between the reinforcing fin and the end face of the second slit is set to a width that prevents the reinforcing fin and the second slit from coming into contact, for example, when the core material is deformed during a major earthquake.

As can be understood from the above description, according to the buckling restraint brace of the present invention, the number of parts in the longitudinal end region of the buckling restraint brace is reduced while ensuring sufficient rigidity in the end region in the longitudinal direction. It is possible to provide a buckling restraint brace that is easy to handle and manufacturable.

It is a perspective view of an example of the core material which forms the buckling restraint brace concerning an embodiment. FIG. 1 is a process diagram of an example of a method for manufacturing a buckling restraint brace. Continuing from FIG. 2, it is a process diagram of an example of a method for manufacturing a buckling restraint brace. 5 is a process diagram of an example of a method for manufacturing a buckling restrained brace following FIG. 3, and also shows an example of a buckling restrained brace according to an embodiment. FIG. 4 is a process diagram of another example of the method for manufacturing a buckling restraint brace following FIG. 3, and is a diagram showing together another example of the buckling restraint brace according to the embodiment. FIG. 13 is a schematic diagram of a vertical cross section of a buckling restraint brace in a direction perpendicular to the axis, illustrating the state in which a pressing force acts from the core material to the restraint material during higher-order mode buckling. FIG. 13 is a schematic diagram of a vertical cross section in the axial direction of a buckling restraint brace, illustrating the state in which a pressing force acts from the core material to the restraint material during higher-order mode buckling.

The buckling restraint brace according to the embodiment will be described below with reference to the attached drawings. Note that in this specification and the drawings, substantially identical components may be designated by the same reference numerals to avoid redundant description.

[Buckling restraint brace according to embodiment]
With reference to FIGS. 1 to 4, an example of the buckling restraint brace according to the embodiment will be described along with a manufacturing method thereof. Here, FIG. 1 is a perspective view of an example of a core material forming a buckling restraint brace according to an embodiment. Further, FIGS. 2 to 4 are process diagrams of an example of a method for manufacturing a buckling restraint brace, and FIG. 4 is a diagram further showing an example of a buckling restraint brace according to an embodiment.

As shown in FIG. 1, the core material 10 of the buckling restraint brace is formed of an elongated steel plate, and the width t1 of the wide surface 11 is the same over the entire length in the longitudinal direction.

The core material 10 is preferably made of steel with a low yield point, such as SN material (rolled steel for architectural structures) or LYP material (very low yield point steel), and by using a core material 10 made of these materials, the yield of the core material 10 improves the earthquake energy absorption.

Since the core material 10 has an elongated rectangular shape in a plan view in which the width t1 of the wide surface 11 is the same throughout the entire longitudinal direction, as shown in Patent Document 1, the width t1 of the wide surface 11 is the same over the entire length. A buckling restraint brace that has a wide portion and eliminates the processing effort required when laser processing the constricted transition portion between them, improves the manufacturing yield of the core material 10, and has the core material 10 as a component. Manufacturability can be improved.

At the center position in the width direction of the two wide faces 11 of the core material 10, reinforcing fins 15 made of steel plates are welded and joined from the longitudinal ends 12 to a predetermined range t2 in the longitudinal direction of the core material 10 in a direction perpendicular to the wide faces 11. The reinforcing fins 15 in the illustrated example have a planar shape in which the width changes in steps along the way, but they may also have a constant width or a shape in which the width changes in two or more steps.

The buckling restraint brace 100 according to the embodiment (see FIG. 4) does not have a pair of flanges or a pair of reinforcing plates connecting the flanges at the longitudinal ends, as in the buckling restraint brace described in Patent Document 1, and instead provides reinforcing fins 15 on the two wide faces 11 at the ends of the core material 10 to make the ends cross-shaped, thereby ensuring the rigidity of the longitudinal ends of the core material 10 (particularly the rigidity in the weak axis direction). Therefore, the length of the reinforcing fins 15 (predetermined range t2) is set to a length that provides the required strength (bending rigidity and shear rigidity) to resist the cross-sectional forces generated at the ends of the core material 10 when the core material 10 is deformed during a major earthquake.

As shown in FIG. 2, an end plate 17 is welded to the longitudinal end portion 12 of the core material 10 shown in FIG. Here, "welding" in this specification includes groove welding (full penetration welding, partial penetration welding), fillet welding, laser welding, etc., as appropriate depending on the strength required for the joint and the joining mode. is selected.

A cylindrical steel protrusion 14 protrudes from the center of the wide surface 11 of the core material 10 in the longitudinal direction. The protrusion 14 is joined to the wide surface 11 by welding or the like.

As shown in FIG. 2, when manufacturing the buckling restraint brace, a steel end plate 17 extending in a direction perpendicular to the longitudinal direction is welded to the longitudinal end portion 12 of the core material 10. When the buckling restraint brace is incorporated into a building frame (not shown), the end plate 17 is bolted to a bracket (not shown) attached to the side surface of a column forming the building frame. A plurality of (two in the illustrated example) bolt holes 17a are provided through which the bolt holes 17a are inserted.

Next, as shown in FIG. 3, an unbonded material (not shown) is placed on each of the two wide surfaces 11 of the core material 10, and a square shape is placed so as to face each wide surface 11 and the unbonded material. A pair of restraining members 30 made of steel pipes are provided.

Here, the unbonded material (not shown) has a thickness that acts as a clearance so that when the building frame deforms, a compressive force acts on the core material 10, causing higher-order mode buckling (wavy deformation) in the out-of-plane direction (weak axis direction).

As the unbond material, for example, an elastic material such as butyl rubber is used. In addition, a projection hole into which the projection 14 of the core material 10 fits is provided at the center position in the longitudinal direction of the unbond material.

On the other hand, the restraining material 30 is formed from a square steel pipe that is rectangular in cross section, and the side corresponding to the long side of the rectangle abuts against the unbonded material. The side of the restraining material 30 that abuts against the unbonded material also has a protrusion hole (not shown) into which the protrusion 14 of the core material 10 fits. Here, an insert plate may be interposed between the unbonded material and the restraining material 30.

At a position of the restraining material 30 corresponding to the reinforcing fin 15 attached to the core material 10, a second slit 33 is provided within a range of a predetermined length t3 from the end 32 to prevent interference with the reinforcing fin 15 when assembling the restraining material 30.

Furthermore, a gap G1 having a predetermined width is provided between the second slit 33 and the end surface of the reinforcing fin 15.

The width of this gap G1 is set so that the reinforcing fin 15 and the end face of the second slit 33 do not come into contact when the core material 10 is deformed in the strong axis direction during a major earthquake, for example. This prevents the reinforcing fin 15 from pressing against the end face of the second slit 33 during a major earthquake, which would damage the end of the restraining material 30.

Furthermore, the length t3 of the second slit 33 is set to a length that prevents the tip of the reinforcing fin 15 from contacting the second slit 33 when the core material 10 receives a compressive force during a major earthquake and shrinks in the longitudinal direction. This also prevents the reinforcing fin 15 from pressing against the end face of the second slit 33 during a major earthquake, damaging the end of the restraining material 30.

Next, as shown in FIG. 4, a pair of stiffeners 50 made of steel plates are welded to both side surfaces 31 of the pair of restraining members 30 on the sides of the core material 10, so that the pair of restraining members 30 are integrated with the pair of stiffeners 50, and a buckling restraint brace 100 is produced in which the core material 10 is surrounded by the pair of restraining members 30 and the pair of stiffeners 50. Here, the stiffener 50 in the illustrated example is formed from a single steel plate having a length similar to that of the restraining member 30, but if the longitudinal length of the core material 10 is long, two stiffeners may be used, and each stiffener may be disposed on the left and right of the longitudinal center position of the core material.

At a position of the stiffener 50 corresponding to the core material 10, a protruding portion 52 is provided that protrudes outward from the end portion 51 of the stiffener 50 over a predetermined range t4 in the longitudinal direction. A gap G2 is provided between the end face of the core material 10 and the inner surface of the protruding portion 52.

The length of the predetermined range t4 and the width of the gap G2 are set to such a length and width that the end surface of the core material 10 and the inner surface of the convex portion 52 do not come into contact, for example, when the core material 10 is deformed in the direction of the strong axis during a major earthquake. This can prevent the end surface of the core material 10 from pressing against the inner surface of the convex portion 52 and damaging the end portion of the stiffening material 50 in the event of a major earthquake.

According to the buckling restraint brace 100, by applying the core material 10 in which the width t1 of the wide surface 11 is the same over the entire area, there is no need to process the constriction shape by laser processing or the like. The manufacturing yield is improved, and the manufacturability of the buckling restraint brace 100 can be improved. In addition, reinforcing fins 15 are provided on the two wide surfaces 11 of the core material 10 from each end 12 to a predetermined range t2 in the longitudinal direction of the core material 10, and flanges and reinforcing plates in the end regions are eliminated. By doing so, the number of parts in the end region is reduced, and the buckling restraint brace 100 has good maneuverability.

On the other hand, FIG. 5 shows another example of the buckling restraint brace according to the embodiment. Here, FIG. 5 is a process diagram of another example of the method for manufacturing the buckling restraint brace following FIG. 3, and is a diagram showing together another example of the buckling restraint brace according to the embodiment.

The illustrated buckling restraint brace 100A differs from the buckling restraint brace 100 in that, instead of a stiffener having a protrusion at its end, the stiffener 50A has a first slit 53 extending over a predetermined longitudinal range t4 from its end 51 at a position corresponding to the core material 10 of the stiffener 50A, and a cover material 55 made of a steel plate surrounding the first slit 53 is joined to its outer surface.

A gap G3 is provided between the end of the core material 10 and the inner surface of the cover material 55 or the first slit 53. Here, the length of the predetermined range t4 and the width of the gap G3 are also changed between the end surface of the core material 10, the inner surface of the cover material 55, and the first slit 53 when the core material 10 is deformed in the strong axis direction during a major earthquake, for example. The length and width are set so that the wall surfaces do not come into contact with each other, so that in the event of a major earthquake, the end surface of the core material 10 will press against the inner surface of the cover material 55 and the wall surface of the first slit 53, and the end portion of the stiffener 50A will It can prevent damage.

Also in the buckling restraint brace 100A, since the core material 10 in which the width t1 of the wide side 11 is the same throughout the entire area is applied, there is no need to process the constriction shape by laser processing or the like. Yield is improved, and the manufacturability of the buckling restraint brace 100 can be improved. In addition, reinforcing fins 15 are provided on the two wide surfaces 11 of the core material 10 from each end 12 to a predetermined range t2 in the longitudinal direction of the core material 10, and flanges and reinforcing plates in the end regions are eliminated. By doing so, the number of parts in the end region is reduced, resulting in the buckling restraint brace 100A with good maneuverability.

Next, with reference to Figures 6A and 6B, we will explain the higher-order mode buckling that occurs in the weak axis direction of the core material 10. Here, Figures 6A and 6B are schematic vertical cross-sectional views in the orthogonal direction and the axial direction of a buckling restraint brace, respectively, which explain the state in which a pressing force acts from the core material to the restraint material during higher-order mode buckling.

FIG. 6A shows the unbonded material 20 interposed between the core material 10 and the restraint material 30. The buckling restraint brace 100 is incorporated into a building frame by having both ends thereof bolted to a connecting jig such as a bracket provided at a corner of the building frame. When the building frame is deformed during an earthquake, an external force such as a horizontal force during the earthquake enters the end of the buckling restraint brace 100 via the connection jig, and the external force is applied from the end of the core member 10 to the entire area. is transmitted as a compressive force N, and the entire area of the core material 10 is plastically deformed, thereby exhibiting energy absorption performance during an earthquake. In other words, when compressive force N is applied to the core material 10, higher-order mode buckling (wavy deformation) occurs in the weak axis direction in the entire region of the core material 10, so that the entire core material 10 can be By uniformly buckling the buckling restraint brace 100, the entire plastic deformation performance of the buckling restraint brace 100 can be exhibited.

As shown in Figures 6A and 6B, a compressive force N acting on the core material 10 causes higher-order mode buckling, and the peaks of the wavy deformation caused by buckling come into contact with the restraining material 30, exerting a compressive force Q on the restraining material 30. Therefore, the local yield strength of the restraining material 30 is set so that the locally acting compressive force Q does not cause localized destruction.

It should be noted that other embodiments may be adopted in which other components are combined with the configurations listed in the above embodiments, and the present invention is not limited to the configurations shown here. In this regard, changes can be made without departing from the spirit of the present invention, and can be appropriately determined depending on the application form.

10: Core material 12: End portion 14: Protrusion 15: Reinforcing fin 17: End plate 17a: Bolt hole 20: Unbonded material 30: Restraint material (square steel pipe)
31: Side 32: End 33: Second slit 50, 50A: Stiffener 51: End 52: Convex 53: First slit 55: Cover material 100, 100A: Buckling restraint brace G1, G2, G3: Gap N: Axial force (compressive force)
Q: Pressing force

Claims (3)

A core material made of a steel plate material, the width of the wide side being the same throughout the entire area;
a pair of restraining members made of square steel pipes, arranged so as to face the two wide surfaces of the core material;
an end plate welded to the longitudinal end of the core material and extending in a direction perpendicular to the longitudinal direction;
a pair of stiffeners welded to both sides of the pair of restraint members on the sides of the core material,
Reinforcing fins extending in a direction perpendicular to the wide surfaces from each end over a predetermined range in the longitudinal direction of the core material are welded to the two wide surfaces of the core material,
At a position of the stiffening material corresponding to the core material, a convex portion extending outward from the end of the stiffening material over a predetermined range in the longitudinal direction is provided, and the core material and the inner part of the convex portion A buckling restraint brace characterized by having a gap between it and the side surface. A core material made of a steel plate material, the width of the wide side being the same throughout the entire area;
a pair of restraining members made of square steel pipes, arranged so as to face the two wide surfaces of the core material;
an end plate welded to the longitudinal end of the core material and extending in a direction perpendicular to the longitudinal direction;
a pair of stiffeners welded to both sides of the pair of restraint members on the sides of the core material,
Reinforcing fins are provided on 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,
A first slit is provided at a position of the stiffening material corresponding to the core material, extending from an end of the stiffening material to a predetermined range in the longitudinal direction, and a cover material surrounding the first slit is provided with a first slit in a position corresponding to the core material. A buckling restraining brace joined to an outer surface of a rigid material, characterized in that a gap is provided between the core material, the inner surface of the cover material, and the first slit. The buckling restraint brace according to claim 1 or 2, characterized in that a second slit is provided in the restraint material at a position corresponding to the reinforcing fin, preventing interference with the reinforcing fin with a gap provided between the restraint material and the reinforcing fin.

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