Buckling restraint brace and method for manufacturing the same

Abstract

To provide a buckling restraint brace with an unbonded member with good adaptability to the shape and dimensions of the buckling restraint brace, and a manufacturing method thereof.SOLUTION: The buckling restraint brace includes: a steel plate-shaped core material 10; a pair of restraint members 30 consisting of square steel tubes arranged opposite the two wide sides 10a of the core material 10; and an unbonded member 20 attached to at least one of the core material 10 and the opposite sides of the restraint member 30. The unbonded member 20 is made of a mixture of a lubricant and a synthetic resin.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a buckling restraint brace and a method for manufacturing the same.

Background Art

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

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

[0004] In this buckling restraint brace, an insertion plate that contacts the restraint material is provided between the plate-like portion and the restraint material, and the restraint material made of a square steel pipe has a corner portion with a curved surface region at the intersection of each surface portion thereof. A welding portion for fixing the restraint material and the insertion plate is provided between the surface of the insertion plate that contacts the restraint material and the corner portion of the restraint material.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] According to the buckling restraint brace described in Patent Document 1, it becomes easy to use a member such as a ready-made square steel pipe as a restraint material, and it is possible to suppress local failure of the restraint material that receives a pressing force from the core material without causing a cost increase.

[0007] By the way, the buckling restraint brace is incorporated into the building structure by being bolted or the like to connection jigs such as brackets and gusset plates provided at the corner parts or the like of the building structure at both ends thereof. When the building structure deforms during an earthquake, an external force such as a horizontal force during the earthquake enters the end of the buckling restraint brace through the bracket or the like, and the external force is transmitted as a compressive force or the like from the end of the core material to the entire area thereof, so that the entire area of the core material plastically deforms, and the energy absorption performance during the earthquake is exhibited. More specifically, when a compressive force acts on the core material, higher-order mode buckling (wave-like deformation) occurs in the weak axis direction over the entire area thereof, and the overall plastic deformation performance of the buckling restraint brace can be exhibited by buckling the entire core material as evenly as possible.

[0008] In the buckling restraint brace described in Patent Document 1, in order to cause the above-described higher-order mode buckling, an unbonded material having a deformation performance 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 so that higher-order mode buckling occurs in this clearance when the core material receives a compressive force.

[0009] When applying the above-described butyl rubber to the unbonded material, in the case of a standard-shaped butyl rubber that is a commercially available product, there generally does not exist a product having dimensions that can be directly applied to the buckling restraint brace. Since the current situation is that cutting and sizing are performed when applying it to the buckling restraint brace, it is difficult to say that the cross-sectional adaptability to the buckling restraint brace is good. For example, there is a problem that it is difficult to correspond to square steel pipes (restraint materials) having various shapes and dimensions.

[0010] The present invention has been made in view of the above problems, and an object thereof is to provide a buckling restraint brace provided with an unbonded material having good adaptability to the shape and dimensions of the buckling restraint brace and a method for manufacturing the same.

Means for Solving the Problems

[0011] To achieve the above object, one aspect of the buckling restraint brace according to the present invention is a steel plate-shaped core material, and a pair of restraint members made of square steel pipes disposed so as to face two wide surfaces of the core material, and an unbonded material attached to at least one of the opposing surfaces of the core material and the restraint member, and the unbonded material is characterized in that it is formed of a mixture of a lubricant and a synthetic resin.

[0012] According to this aspect, since the unbonded material is not a fixed commercially available product but is formed of a mixture of a lubricant and a synthetic resin, the unbonded material is formed by applying it to at least one of the opposing surfaces of the core material and the restraint member by coating, spraying, etc. Therefore, it becomes a buckling restraint brace provided with an unbonded material having good adaptability to the shape and dimensions of the buckling restraint brace.

[0013] In addition, "at least one of the opposing surfaces of the core material and the restraint member" means that it includes both of the opposing surfaces (wide surfaces) of the core material and the restraint material and either one of the opposing surfaces of the core material and the restraint plate.

[0014] In the case of a conventional unbonded material made of butyl rubber or the like, by using its thickness as a clearance, it is possible to cause higher-order mode buckling in this clearance when the core material receives a compressive force. On the other hand, in this aspect where the unbonded material is formed by coating on at least one of the opposing surfaces of the core material and the restraint member, a gap (clearance) for causing higher-order mode buckling of the core material is provided on one side of the unbonded material.

[0015] In the core material, slits may be provided on the wide surfaces of the core material in order to effectively cause buckling of higher-order modes in the minor axis direction. And, since the strength in the major axis direction of the core material is weakened by providing slits on the wide surfaces in this way, spacers may be inserted into the slits on the wide surfaces as necessary.

[0016] Also, another aspect of the buckling restraint brace according to the present invention is a plate-shaped core material made of steel, a pair of inner insertion plates arranged so as to face two wide surfaces of the core material, a pair of restraint members made of square steel pipes arranged so as to face the wide surfaces of the pair of inner insertion plates, and an unbonded material attached to at least one of the opposing surfaces of the core material and the inner insertion plate, characterized in that the unbonded material is formed of a mixture of a lubricant and a synthetic resin.

[0017] According to this aspect, in the form where the inner insertion plate is arranged between the core material and the restraint member, since the unbonded material is formed by applying it to at least one of the opposing surfaces of the core material and the inner insertion plate by coating, spraying, etc., it becomes a buckling restraint brace provided with an unbonded material having good cross-sectional adaptability to the buckling restraint brace. Further, since, for example, a steel inner insertion plate is interposed between the unbonded material and the restraint member, the pressing force due to buckling of higher-order modes in the minor axis direction of the core material does not directly act on the restraint member, and it is possible to effectively suppress the restraint member from being locally damaged.

[0018] Here, "at least one of the opposing surfaces of the core material and the inner insertion plate" means including both of the opposing surfaces (wide surfaces) of the core material and the inner insertion plate and either one of the opposing surfaces of the core material and the inner insertion plate.

[0019] Also, in another aspect of the buckling restraint brace according to the present invention, a gap for buckling deformation of the core material is provided on the side opposite to the attachment surface of the unbonded material to the core material, the restraint member, or the inner insertion plate.

[0020] According to this aspect, since the unbonding material is formed by coating on at least one of the opposing surfaces of the core material and the restraining material, a clearance for buckling deformation is provided, making it possible to cause buckling in the higher-order modes of the core material.

[0021] Also, one aspect of the method for manufacturing a buckling restraining brace according to the present invention is the method for manufacturing the buckling restraining brace, wherein the admixture is applied or sprayed onto the attachment surface of the unbonding material to the core material, the restraining material, or the insertion plate to form the unbonding material, and it is characterized in that it is assembled with the clearance provided on the side opposite to the attachment surface in the unbonding material.

[0022] According to this aspect, since the unbonding material is formed by applying or spraying the admixture onto at least one attachment surface of the core material, the restraining material, and the insertion plate, a buckling restraining brace provided with an unbonding material having good cross-sectional adaptability to the buckling restraining brace can be manufactured. Furthermore, since the unbonding material is formed by coating, it is possible to guarantee the occurrence of buckling in the higher-order modes of the core material by providing a clearance for buckling deformation.

Advantages of the Invention

[0023] As can be understood from the above description, according to the buckling restraining brace and the method for manufacturing the same of the present invention, it is possible to provide a buckling restraining brace provided with an unbonding material having good adaptability to the shape and dimensions of the buckling restraining brace.

Brief Description of the Drawings

[0024]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5A

Figure 5B

Mode for Carrying Out the Invention

[0025] Hereinafter, the buckling restraint brace according to the embodiment will be described with reference to the accompanying drawings. In this specification and the drawings, substantially the same components may be denoted by the same reference numerals, and redundant descriptions may be omitted.

[0026] [Buckling Restraint Brace According to the Embodiment and Its Manufacturing Method] With reference to FIGS. 1 to 5, an example of the buckling restraint brace according to the embodiment and its manufacturing method will be described. Here, FIG. 1 is an exploded perspective view of an example of the buckling restraint brace according to the embodiment, and FIG. 2 is a longitudinal sectional view in the direction orthogonal to the axis of the state before assembly of the buckling restraint brace according to the embodiment. Further, FIG. 3 is a perspective view of an example of the buckling restraint brace according to the embodiment, and FIG. 4 is a longitudinal sectional view in the direction orthogonal to the axis of the assembled state of the buckling restraint brace according to the embodiment.

[0027] The buckling restraint brace 100 includes a core material 10, a pair of restraint materials 30 disposed so as to face two wide surfaces 10a of the core material 10, and an unbonded material 20 interposed between the core material 10 and the restraint material 30. Here, in addition to the illustrated example, a form in which an insertion plate is interposed between the unbonded material 20 and the restraint material 30 may be adopted.

[0028] The core material 10 is preferably formed of a steel material with a low yield point such as SN material (rolled steel for building structures) or LYP material (extra-low yield point steel). By applying the core material 10 made of these materials, the earthquake energy absorption performance due to the yield of the core material 10 is improved.

[0029] The core material 10 is formed of an elongated steel plate, and has a narrow-width portion 11 where the width of the wide-width surface 10a is relatively narrow on the central side in the longitudinal direction, and a wide-width portion 12 where the width of the wide-width surface 10a is relatively wide on the end side in the longitudinal direction.

[0030] Since the core material 10 has the narrow-width portion 11 on the central side in the longitudinal direction and the wide-width portion 12 on the end side in the longitudinal direction, the narrow-width portion 11 on the central side can be made into a region where plasticization is easy, and furthermore, the plasticization region can be limited to the narrow-width portion 11 on the central side.

[0031] At the central position of the narrow-width portion 11 of the core material 10, steel cylindrical protrusions 15 project from the two wide-width surfaces 10a of the narrow-width portion 11. The protrusions 15 are joined to the wide-width surface 10a of the narrow-width portion 11 by welding or the like.

[0032] Also, elongated slits 14 are provided on both sides of the protrusions 15 of the narrow-width portion 11 of the core material 10, and steel spacers 17 are inserted into the slits 14 in the X1 direction.

[0033] The slits 14 are pores for adjusting the yield strength of the core material 10, and the spacers 17 function as internal deformation prevention materials for preventing the core material 10 from deforming internally (deforming in the strong axis direction) due to the provision of the slits 14. The spacers 17 inserted into the slits 14 are position-regulated by a pair of restraint materials 30.

[0034] At the wide-width portions 12 at both ends of the core material, joining plates 13 each composed of a pair of steel plates, which are joined to other members orthogonally to the wide-width surface 10a, are joined by welding or the like.

[0035] The wide-width portion 12 and the joint plate 13 are each provided with bolt holes 12a and 13a, which are aligned with the bolt holes of connection jigs (other members) such as brackets and gusset plates that project into the plane from the corner portions of a building structure (not shown), and are bolted together.

[0036] A reinforcing plate 18 made of a steel plate is joined to the pair of joint plates 13 by welding or the like, and the end portion of the restraint material 30 is accommodated in the space formed by the wide-width portion 12 of the core material 10, the pair of joint plates 13, and the reinforcing plate 18.

[0037] The unbonding material 20 is formed of a mixture of a lubricant and a synthetic resin. Here, the lubricant includes a solid lubricant and a liquid lubricant. Examples of the solid lubricant include molybdenum disulfide (MoS2), graphite (carbon), and fluororesin (PTFE: polytetrafluoroethylene). By forming a solid lubricant film on the friction surface, direct contact between the friction surface materials can be suppressed, and the occurrence of galling can be suppressed. On the other hand, an example of the liquid lubricant is lubricating oil. Examples of the synthetic resin (paint) include epoxy resin, silicone resin, acrylic resin, acrylic silicone resin, chlorinated rubber resin, silicone resin, phenol resin, phthalic acid resin, unsaturated polyester resin, and polyurethane resin.

[0038] In FIG. 1, the unbonding material 20 is schematically shown attached in the X2 direction to the opposing surface of the restraint material 30 to the core material 10. However, in actuality, as shown in FIG. 4, a mixture of a lubricant and a synthetic resin is applied or sprayed onto the opposing surface of the restraint material 30 with a brush or the like to form an unbonding material 20 having a thin and thick shape with a protruding hole 20a in the center.

[0039] Here, in the illustrated example, the unbonding material 20 is formed on the opposing surface of the restraint material 30 to the core material 10. However, the unbonding material may be formed on the opposing surface of the core material 10 to the restraint material 30, or the unbonding material may be formed on both opposing surfaces of the restraint material 30 and the core material 10. Furthermore, the unbonding material may also be formed on the left and right narrow-width surfaces of the core material 10.

[0040] In addition, in the form where the insertion plate is interposed between the restraint member 30 and the core member 10, there are also forms in which the unbonded material is formed on the surface of the insertion plate facing the core member 10, or the unbonded material is formed on the opposing surfaces of both the insertion plate and the core member 10.

[0041] Compared with the unbonded material made of conventional butyl rubber or the like, the unbonded material 20 formed of a mixture of a lubricant and a synthetic resin can achieve a low friction with a coefficient of friction: μ = 0.04, and can achieve a heat resistance temperature of about 300°C.

[0042] Also, since the unbonded material 20 is formed by applying a mixture of a lubricant and a synthetic resin to the side surface of the restraint member 30 or the side surface (wide surface 10a) of the core member 10, etc., the adaptability to the restraint member 30 and the core member 10 of various shapes and dimensions is improved, and the labor of cutting commercially available products according to the shapes and dimensions of the restraint member 30 etc. like the conventional unbonded material made of butyl rubber or the like can be eliminated.

[0043] As shown in FIG. 4, a gap 25 of about 1 mm is formed, for example, between the unbonded material 20 formed on the opposing surface of the restraint member 30 and the core member 10 (on the side opposite to the mounting surface of the unbonded material 20). When the building structure incorporating the buckling restraint brace 100 deforms, a compressive force acts on the core member 10 inside this gap 25, and higher-order mode buckling (wavy deformation) in the out-of-plane direction (weak axis direction) occurs in the narrow portion 11.

[0044] The restraint member 30 is formed of a rectangular steel pipe in cross-section. Among the restraint members 30, a protrusion hole 30a into which the protrusion 15 of the core member 10 fits is also provided on the side surface where the unbonded material 20 is formed.

[0045] On the side of the core member 10, both sides of a pair of restraint members 30 (the side surfaces corresponding to the short sides of the rectangle) are connected by a stiffening member 50 composed of a pair of steel plates by welding or the like, and the core member 10 is surrounded by a pair of restraint members 30 and a pair of stiffening members 50.

[0046] Next, with reference to FIG. 5, the higher-order mode buckling occurring in the weak axis direction of the core member 10 will be described.

[0047] The buckling restraint brace 100 is incorporated into the building structure by being bolted or the like to connection fixtures provided at the corner portions or the like of the building structure at both of its ends. When the building structure deforms during an earthquake, an external force such as a horizontal force during the earthquake enters the end of the buckling restraint brace 100 through the connection fixture, and the external force is transmitted as a compressive force N from the end of the core material 10 to the entire area thereof. As a result, the entire area of the core material 10 undergoes plastic deformation, and the energy absorption performance during an earthquake is exhibited. In other words, when a compressive force N acts on the core material 10, higher-order mode buckling (wavy deformation) occurs in the weak axis direction over the entire area of the core material 10, and by buckling the entire core material 10 as evenly as possible, the overall plastic deformation performance of the buckling restraint brace 100 can be exhibited.

[0048] As shown in FIG. 5B, higher-order mode buckling occurs due to the compressive force N acting on the core material 10, and the peaks of the wavy deformation due to the buckling come into contact with the restraint material 30, applying a pressing force Q to the restraint material 30.

[0049] The local yield strength of the restraint material 30 is set so as not to cause local fracture with respect to the locally acting pressing force Q.

[0050] In addition, other embodiments in which other components are combined with the configurations and the like described in the above embodiments may be possible, and the present invention is not limited to the configurations shown here in any way. In this regard, it can be changed without departing from the gist of the present invention, and can be appropriately determined according to the application form.

Explanation of Reference Numerals

[0051] 10: Core material 10a: Wide-width surface 11: Narrow-width portion 12: Wide-width portion 12a: Bolt hole 13: Joint plate 13a: Bolt hole 14: Slit 15: Protrusion 17: Spacer 18: Reinforcing plate 20: Unbonding material 20a: Protrusion hole 25: Gap 30: Restraining material (square steel pipe) 30a: Protrusion hole 50: Stiffening material 100: Buckling restraining 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 so as to face two wide surfaces of the core material, and an unbonding material attached to at least one of the opposing surfaces of the core material and the restraint members, wherein the unbonding material is formed of a mixture of a lubricant and a synthetic resin, and a gap for buckling deformation of the core material is provided on the side opposite to the attachment surface of the unbonding material to the core material or the restraint member. A buckling restraint brace characterized by this.

2. a steel plate-shaped core material, a pair of insertion plates disposed so as to face two wide surfaces of the core material, a pair of restraint members made of square steel pipes disposed so as to face the wide surfaces of the pair of insertion plates, and an unbonding material attached to at least one of the opposing surfaces of the core material and the insertion plates, wherein the unbonding material is formed of a mixture of a lubricant and a synthetic resin, and a gap for buckling deformation of the core material is provided on the side opposite to the attachment surface of the unbonding material to the core material or the insertion plate. A buckling restraint brace characterized by this.

3. A method for manufacturing the buckling restraint brace according to Claim 1 or 2, wherein the mixture is applied or sprayed onto the attachment surface of the unbonding material to the core material, the restraint member, or the insertion plate to form the unbonding material, and the assembly is performed with the gap provided on the side opposite to the attachment surface of the unbonding material. A method for manufacturing a buckling restraint brace characterized by this.

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