Buckling restraint brace

Abstract

To provide a buckling restraint brace having a restraint member instead of an unbonded member of shaped butyl rubber, which has a mechanism to prevent local destruction caused by the pressing force received from the core member and a function as an unbonded member.SOLUTION: A buckling restraint brace 100 includes: a core member 10 having a steel plate shape; a pair of restraint members 30 made of square steel pipes, which are arranged so as to face the two wide faces the core member 10 has; and an insertion plate 20 that is interposed between the core member 10 and the restraint member 30. The strength and hardness of the insertion plate 20 are relatively higher than those of the core member 10 and the restraint member 30.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Buckling-restrained braces with buckling prevention measures have been used as braces that form building frames (column-beam frames, roof frames, etc.). Buckling-restrained braces come in a variety of stiffening forms, including a form in which the periphery of a steel core is stiffened only with steel plates, a form in which the periphery of a steel core is stiffened with RC (Reinforced Concrete), and a form in which the periphery of a steel core is covered with steel and mortar.

[0003] Here, Patent Document 1 proposes a buckling-restrained brace in which a core member is restrained by restraining members formed of a pair of square steel pipes, and which does not cause local destruction in the restraining members that receive a pressing force from the core member. Specifically, the buckling-restrained brace includes a core member that has joints at both ends of the plate-like portion for joining to other members, and restraining members arranged opposite each face perpendicular to the weak axis direction of the plate-like portion.

[0004] In this buckling restraint brace, a steel plate that comes into contact with the restraining material is provided between the plate-like portion and the restraining material, and the restraining material made of a square steel tube has corners with curved areas at the intersections of its surface portions. Welds that secure the restraining material and the steel plate are provided between the surface of the steel plate that comes into contact with the restraining material and the corners of the restraining material. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6445862 Summary of the Invention [Problem to be solved by the invention]

[0006] The buckling restraint brace described in Patent Document 1 makes it easy to use components such as prefabricated square steel pipes as restraint materials, making it possible to suppress localized failure of the restraint material when subjected to compressive force from the core material, without incurring high costs.

[0007] The buckling restrained brace is assembled into the building frame by bolting both ends to connecting fixtures such as brackets and gusset plates provided at the corners of the building frame. When the building frame is deformed during an earthquake, an external force such as a horizontal force during an earthquake enters the end of the buckling restrained brace through the bracket, etc., and the external force is transmitted from the end of the core material to the entire area as a compressive force, etc., causing the entire core material to plastically deform, thereby demonstrating the energy absorption performance during an earthquake. More specifically, when a compressive force acts on the core material, a higher-order mode buckling (wave-like deformation) occurs in the weak axis direction throughout the entire area, and the entire core material is buckled as evenly as possible, thereby enabling the entire buckling restrained brace to demonstrate its plastic deformation performance.

[0008] In the buckling restraint brace described in Patent Document 1, in order to cause the above-mentioned higher mode buckling, an unbonded material with deformable properties such as butyl rubber is interposed between the wide surface of the core material and the restraint material, and the thickness of the unbonded material is used as a clearance, within which higher mode buckling occurs when the core material is subjected to a compressive force.

[0009] When applying the above-mentioned butyl rubber to an unbonded material, there are generally no standardized butyl rubber products available on the market that are available in sizes that can be directly applied to buckling restraint braces, and the current situation is that when applying to a buckling restraint brace, the rubber must be cut to fit the dimensions. As a result, it is difficult to say that the cross-sectional adaptability to buckling restraint braces is good, and there are issues such as it being difficult to use for square steel pipes (restraint materials) of various shapes and sizes.

[0010] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a buckling restraint brace that has a mechanism for preventing localized damage caused by the pressing force that the restraint material receives from the core material and a component that functions as an unbonded material, instead of an unbonded material made of standard butyl rubber. [Means for solving the problem]

[0011] In order to achieve the above object, one aspect of the buckling restraint brace according to the present invention is to A steel plate-shaped core material, A pair of restraining members made of square steel pipes arranged to face the two wide surfaces of the core material; An insert plate is interposed between the core material and the restraint material, The strength and hardness of the insert plate are relatively high compared to the core material and the restraining material.

[0012] According to this embodiment, by interposing an insert plate between the core material and the restraint material, which has relatively higher strength and hardness than the core material and the restraint material, the insert plate prevents localized damage caused by the pressing force that the restraint material receives from the core material, and also functions as an unbonded material, i.e., prevents friction when the core material and the restraint material slide against each other when a building frame incorporating a buckling restraint brace deforms during an earthquake.

[0013] Here, "the strength and hardness of the insert plate are relatively high compared to the core material and the restraining material" includes relationships in which the relationship between their respective strengths and hardnesses is inner plate > core material = restraining material, inner plate > core material > restraining material, or inner plate > restraining material > core material.

[0014] In addition, in order to effectively induce higher-order mode buckling in the weak axis direction of the core material, slits may be provided in the broad surface of the core material. Since providing slits in the broad surface in this manner weakens the strength of the core material in the strong axis direction, spacers may be inserted into the slits in the broad surface as necessary.

[0015] Another aspect of the buckling restraint brace according to the present invention is The core material, the restraint material, and the insert plate are all formed from one of SS material, SN material, and SM material, and the insert plate is formed from a material with relatively high strength and high hardness.

[0016] According to this embodiment, the core material, the restraining material, and the insert plate are all made of SS (Steel Structure) material (rolled steel for general structure), SN (Steel New) material (rolled steel for architectural structure), and SM (Steel Marine) material (rolled steel for welded structure), which are generally available on the market and are as inexpensive as possible, and by changing the steel type of the core material, the restraining material, and the insert plate, it is possible to reduce the manufacturing cost while varying their strength and hardness. Here, as the material for the core material, etc., any product certified by the Minister of Land, Infrastructure, Transport and Tourism may be used.

[0017] Another aspect of the buckling restraint brace according to the present invention is The core material and the restraint material are formed from one of SS material, SN material, and SM material, and the inner plate is formed from SC material.

[0018] According to this embodiment, the core material and restraint material are formed from one of SS material, SN material, or SM material which are generally commercially available and as inexpensive as possible, and the insertion plate is formed from SC (Steel Carbon) material (carbon steel material for mechanical structures) which is also generally commercially available and as inexpensive as possible. Since SC material generally has greater strength and hardness than SS material, etc., it is possible to reduce production costs while differing the strength and hardness.

[0019] In another aspect of the buckling restrained brace according to the present invention, The insert plate is characterized in that a gap is provided on the side opposite to the attachment surface to the core material or the restraint material to allow for buckling deformation of the core material.

[0020] According to this aspect, an insertion plate is attached to at least one of the opposing surfaces of the core material and the restraint material, and a clearance for buckling deformation is provided between the insertion plate and the other member, so that it becomes possible to cause buckling of higher-order modes of the core material. In this aspect, the insertion plate can be connected to either the core material or the restraint material on one of its surfaces by spot welding, an adhesive, or the like.

[0021] Also, in another aspect of the buckling restraint brace according to the present invention, A pair of joint plates, which are joined to other members orthogonally to the wide-width surface, are fixed to both ends of the core material, A reinforcing plate is fixed to the pair of joint plates, and the end portion of the restraint material is housed in a space formed by the wide-width surface, the pair of joint plates, and the reinforcing plate.

[0022] According to this aspect, a pair of joint plates orthogonal to the wide-width surface are fixed at both ends of the core material, a reinforcing plate is fixed to the pair of joint plates, and the end portion of the restraint material is housed in a space formed by the wide-width surface, the pair of joint plates, and the reinforcing plate, so that a buckling restraint brace having a high-strength end structure is obtained. Here, examples of the other member to which the joint plate is joined include connection fixtures such as brackets and gusset plates that project into the plane from the corner portions of the building structure. Also, when the end portion of the core material is a web, the pair of joint plates orthogonal to this web become a pair of flanges.

[0023] Also, another aspect of the buckling restraint brace according to the present invention is 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 surrounded by the pair of restraint materials and the pair of supplementary stiffening members.

[0024] According to this aspect, by connecting both sides of the pair of restraint materials on the side of the core material with a pair of supplementary stiffening members, 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 restraint brace of the present invention can provide a buckling restraint brace that has a mechanism for preventing localized damage caused by the pressing force that the restraint material receives from the core material, instead of an unbonded material made of fixed butyl rubber, and a component that functions as an unbonded material. [Brief description of the drawings]

[0026] [Figure 1] FIG. 1 is an exploded perspective view of an example buckling restrained brace according to embodiments. [Diagram 2] FIG. 2 is a longitudinal cross-sectional view of a buckling restraint brace according to an embodiment in a pre-assembly state taken in a direction perpendicular to the axis. [Diagram 3] FIG. 1 is a perspective view of an example of a buckling restrained brace according to embodiments. [Figure 4] FIG. 2 is a longitudinal cross-sectional view of the buckling restraint brace according to the embodiment in an assembled state taken in a direction perpendicular to the axis. [Figure 5A] 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. [Figure 5B] 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. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Hereinafter, a buckling restraint brace according to an embodiment will be described with reference to the accompanying drawings. In this specification and the drawings, substantially identical components are designated by the same reference numerals to avoid redundant description.

[0028] [Buckling restraint brace according to embodiment] An example of a buckling restrained brace according to an embodiment and a method for manufacturing the same will be described with reference to Figures 1 to 5. Here, Figure 1 is an exploded perspective view of an example of a buckling restrained brace according to an embodiment, and Figure 2 is a longitudinal cross-sectional view in a direction perpendicular to the axis of the buckling restrained brace according to an embodiment in a pre-assembled state. Also, Figure 3 is a perspective view of an example of a buckling restrained brace according to an embodiment, and Figure 4 is a longitudinal cross-sectional view in a direction perpendicular to the axis of the buckling restrained brace according to an embodiment in an assembled state.

[0029] The buckling restrained brace 100 has a core material 10, a pair of restraining members 30 arranged to face two wide surfaces 10a of the core material 10, and an insert plate 20 interposed between the core material 10 and the restraining members 30. In other words, unlike conventional buckling restrained braces, it does not have an unbonded material made of fixed butyl rubber.

[0030] The core material 10 is formed from a long, thin steel plate and has a narrow width portion 11 at the center of its longitudinal direction where the width of the wide surface 10a is relatively narrow, and a wide width portion 12 at the end of its longitudinal direction where the width of the wide surface 10a is relatively wide.

[0031] Since the core material 10 has a narrow width portion 11 at the center of its longitudinal direction and a wide width portion 12 at each end of the longitudinal direction, the narrow width portion 11 at the center can be made into a region that is easily plasticized, and further, the plasticization region can be limited to the narrow width portion 11 at the center.

[0032] A cylindrical steel protrusion 15 protrudes from the two wide surfaces 10a of the narrow portion 11 at the center of the narrow portion 11 of the core material 10. The protrusion 15 is joined to the wide surfaces 10a of the narrow portion 11 by welding or the like.

[0033] Further, on both sides of the projection 15 of the narrow portion 11 of the core material 10, a long and narrow slit 14 is provided, and a steel spacer 17 is inserted into the slit 14 in the X1 direction.

[0034] The slits 14 are small holes for adjusting the strength of the core material 10, and the spacers 17 function as internal deformation prevention materials that prevent the core material 10 from deforming inward (deformation in the strong axis direction) due to the provision of the slits 14. The position of the spacers 17 inserted into the slits 14 is restricted by a pair of restraining members 30.

[0035] A pair of joining plates 13 made of steel plates are joined by welding or the like to the wide portions 12 at both ends of the core material so as to be joined to other members perpendicular to the wide surfaces 10a.

[0036] The wide portion 12 and the connecting plate 13 are provided with bolt holes 12a, 13a, respectively, which are aligned with the bolt holes of connecting fixtures (other components) such as brackets and gusset plates that protrude into the structural surface from corners, etc. of the building frame (not shown), and are bolted together.

[0037] A reinforcing plate 18 made of a steel plate is joined to the pair of joining plates 13 by welding or the like, and the end of the restraint material 30 is accommodated in the space formed by the wide portion 12 of the core material 10, the pair of joining plates 13, and the reinforcing plate 18.

[0038] By interposing the insert plate 20 between the core material 10 and the restraint material 30, localized damage caused by the restraint material 30 receiving direct pressure from the core material 10 can be prevented when a building frame incorporating the buckling restraint brace 100 is deformed during an earthquake.

[0039] Here, the materials from which the inner plate 20, the core material 10 and the restraining material 30 are formed are set so that the strength and hardness of the inner plate 20 are relatively higher than those of the core material 10 and the restraining material 30.

[0040] For example, the type of metal or the type of steel may be changed so as to relatively increase the strength and hardness of the inner plate 20. Examples of the metal type include steel, aluminum, stainless steel, copper, titanium, and lead.

[0041] When changing the type of steel, there is a configuration in which the core material 10, the restraint material 30, and the inner plate 20 are all formed from one of SS material, SN material, or SM material, with the inner plate 20 being formed from a relatively high strength and high hardness SS material or the like, or a configuration in which the core material 10 and the restraint material 30 are formed from one of SS material, SN material, or SM material, and the inner plate 20 is formed from an SC material.

[0042] Looking at SS materials, there are SS330, SS400, SS490, SS540, etc., with SS400 and SS490 being the most widely used.

[0043] Therefore, in a configuration in which the core material 10, the restraint material 30, and the inner plate 20 are all formed from SS material, it is preferable to use SS400 for the core material 10 and the restraint material 30 and SS490 for the inner plate 20, as this reduces manufacturing costs.

[0044] On the other hand, SC materials include S45C, S50C, S55C, S60C, etc., with S45C being the most widely used.

[0045] Therefore, it is preferable to use, for example, SS400 or SS490 for the core material 10 and the restraining material 30, and S45C for the inner plate 20, since this reduces manufacturing costs.

[0046] When metal members made of the same metal are brought into contact with each other to form a sliding surface, the sliding surfaces of the two metal members are plastically deformed so as to mesh with each other, which may cause galling or seizure. In the sliding surfaces of metal members made of the same metal, the oxide film on the sliding surface is peeled off to expose the metal, which is easily welded by diffusion bonding, and when welded, unevenness may occur on the metal surface. If the hardness of both metals is the same, the unevenness of each metal meshes with each other, so by making the hardness of both metals different, for example, the relatively hard metal is cut and deformed by cutting the soft metal, and the metal becomes smooth by repeated cutting.

[0047] Therefore, in the buckling restraint brace 100, an insert plate 20 is interposed between the core material 10 and the restraint material 30. The insert plate 20 is made of a different metal or steel type and has greater strength and hardness than the core material 10 and the restraint material 30. This prevents bidding between the core material 10 and the insert plate 20, and between the insert plate 20 and the restraint material 30, when a building frame in which the buckling restraint brace 100 is incorporated is deformed during an earthquake.

[0048] In addition, by eliminating the need for a fixed butyl rubber unbonding material, after the buckling restraint brace 100 is assembled, it is possible to perform electrocoating by immersing the entire brace in a water-soluble solution and passing a direct current through it to form a coating.

[0049] In conventional buckling restraint braces equipped with unbonded material made of butyl rubber, the butyl rubber deteriorates due to electrochemical coating, so spray coating is applied to each part, and then the spray-coated parts are assembled to manufacture the buckling restraint brace, which requires a lot of manufacturing work. Furthermore, when assembly after spray coating is performed by welding, touch-up rust-preventive coating is applied after welding, but this touch-up rust-preventive coating also requires manufacturing work.

[0050] According to the buckling restrained brace 100, the entire assembled buckling restrained brace can be electrocoated, eliminating the need for touch-up anti-rust coating, and dramatically improving production efficiency.

[0051] From the above, since the insert plate 20 has both the function of preventing localized damage caused by the pressing force that the restraint material 30 receives from the core material 10 and the function of acting as an unbonding material, it can also be called an insert plate that can also be used as an unbonding material.

[0052] 1, the inner plate 20 is attached to the restraining member 30 in the X2 direction and fixed by spot welding, adhesive, etc. Here, the inner plate 20 may be fixed to the core member 10.

[0053] 4, a gap 25 of, for example, about 1 mm is formed between the core material 10 and the inner plate 20 formed on the opposing surface of the restraint material 30 (opposite the mounting surface of the inner plate 20). Inside this gap 25, a compressive force acts on the core material 10 when the building frame incorporating the buckling restraint brace 100 deforms, causing high-order mode buckling (wavy deformation) in the out-of-plane direction (weak axis direction) in the narrow width portion 11.

[0054] In the buckling restrained brace 100, the thickness of the insert plate 20 can be made as thin as possible because the insert plate 20 has a relatively high strength and hardness compared to the core material 10, etc. Therefore, the buckling restrained brace 100 formed with the gap 25 has an overall thickness that is as thin as possible.

[0055] The restraining member 30 is formed of a square steel pipe having a rectangular cross section. A projection hole 30a into which the projection 15 of the core member 10 fits is also provided on the side of the restraining member 30 to which the inner plate 20 is attached.

[0056] On the sides of the core material 10, both sides (sides corresponding to the short sides of the rectangle) of the pair of restraint materials 30 are connected by welding or the like to a pair of stiffening materials 50 made of steel plates, and the core material 10 is surrounded by the pair of restraint materials 30 and the pair of stiffening materials 50.

[0057] Next, with reference to FIG. 5, a description will be given of higher-order mode buckling occurring in the weak axis direction of the core material 10.

[0058] The buckling restrained brace 100 is assembled into the building frame by bolting both ends to connecting jigs provided at the corners 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 restrained brace 100 through the connecting jig, and the external force is transmitted as a compressive force N from the end of the core material 10 to the entire area, causing the entire core material 10 to plastically deform, thereby exerting its energy absorption performance during an earthquake. In other words, when a compressive force N acts on the core material 10, a higher-order mode buckling (wave-like deformation) occurs in the weak axis direction throughout the entire core material 10, and the entire core material 10 is buckled as evenly as possible, thereby allowing the entire buckling restrained brace 100 to exert its overall plastic deformation performance.

[0059] As shown in FIG. 5B, a compressive force N acting on the core material 10 causes buckling in a higher mode, and the peaks of the wavy deformation caused by the buckling apply a pressing force Q to the inner plate 20.

[0060] The pressing force Q acts on the inner plate 20, and then spreads inside the inner plate 20 and acts on the restraining member 30, thereby preventing localized damage to the restraining member 30 due to the pressing force Q.

[0061] In addition, the present invention is not limited to the configuration shown here, and may be implemented in other embodiments in which other components are combined with the configurations and the like of the above-mentioned embodiment. In this regard, the present invention may be modified within the scope of the gist of the present invention, and may be appropriately determined according to the application form. [Explanation of symbols]

[0062] 10: Core material 10a: Wide surface 11: Narrow section 12: Wide section 12a: Bolt hole 13: Joint plate 13a: Bolt hole 14: Slit 15: Protrusion 17: Spacer 18: Reinforcement plate 20: Insert plate (also used as unbonded material) 20a:Protrusion hole 25: Gap 30: Restraint material (square steel pipe) 30a:Protrusion hole 50: Stiffener 100: Buckling restraint brace N: Axial force (compressive force) Q: Pressing force

Claims

1. a steel plate-shaped core material, a pair of restraint members made of square steel pipes disposed to face two wide surfaces of the core material, and an insertion plate interposed between the core material and the restraint members, wherein the strength and hardness of the insertion plate are relatively higher than those of the core material and the restraint members, characterized in that it is a buckling restraint brace.

2. The core material, the restraint members, and the insertion plate are all formed of any one of SS material, SN material, and SM material, and the insertion plate is formed of a relatively high-strength and high-hardness material, characterized in that it is the buckling restraint brace according to Claim 1.

3. The core material and the restraint members are formed of any one of SS material, SN material, and SM material, and the insertion plate is formed of SC material, characterized in that it is the buckling restraint brace according to Claim 1.

4. A gap for buckling deformation of the core material is provided on the side of the insertion plate opposite to the attachment surface to the core material or the restraint member, characterized in that it is the buckling restraint brace according to any one of Claims 1 to 3.

5. A pair of joint plates that are joined to other members perpendicular to the wide surfaces are fixed to both ends of the core material, a reinforcing plate is fixed to the pair of joint plates, and the end portion of the restraint member is accommodated in the space formed by the wide surface, the pair of joint plates, and the reinforcing plate, characterized in that it is the buckling restraint brace according to any one of Claims 1 to 4.

6. On the side of the core material, a pair of supplementary stiffening members connect both sides of the pair of restraint members, wherein the core material is surrounded by the pair of restraint members and the pair of supplementary stiffening members, characterized in that it is the buckling restraint brace according to any one of Claims 1 to 5.

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