Buckling Restrained Brace

Abstract

To provide a buckling restraint brace suitable for use in a frame structure of a wooden building and the like, in which, for example, during a major earthquake, the frame and the buckling restraint brace deform outside a structural plane, and a core material that forms the buckling restraint brace pushes a restraint plate that forms a wooden restraint material, thereby eliminating the occurrence of cracks in a side plate pulled by the restraint plate.SOLUTION: The buckling restraint brace includes: a steel plate-shaped core material 10; a pair of wooden restraint plates 21 arranged to face two wide surfaces 11a of the core material 10; and a wooden restraining member 20 formed by a pair of wooden side plates 22 arranged to face two narrow surfaces 11b of the core member 10 and connected to the pair of restraint plates 21. A non-contact groove 23 that does not contact the wide surfaces 11a of the core material 10 is provided at an end of the restraint plate 21, and an area of the restraint plate 21 other than the non-contact groove 23 contacts the wide surface 11a of the core material 10.SELECTED DRAWING: Figure 3

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] Recently, efforts have been made to improve the fire resistance and earthquake resistance of wooden buildings (wooden houses, wooden warehouses, wooden stadiums, etc.). Wooden houses inherently have advantages such as a high degree of freedom in layout and design, the soothing effect of natural wood, the moisture-regulating effect of wood, and generally lower construction costs compared to steel-framed or reinforced concrete structures depending on the building purpose such as housing, but the above-mentioned improvement in fire resistance and earthquake resistance is one of the factors that has increased the attention of wooden buildings such as wooden houses. When the above-mentioned conventional buckling restraint brace is incorporated into the frame of such a wooden house, wooden columns and beams are mixed with buckling restraint braces with metal or concrete stiffeners, which inevitably results in an unbalanced appearance.

[0004] One possible solution is to cover the entire buckling restraint brace with a wooden or paper panel, making the metal or concrete stiffener invisible from the outside, but this requires a great deal of work and labor, which raises concerns about increased construction costs.In addition, conventional buckling restraint braces tend to be heavy because they use a lot of metal, concrete, mortar, etc., and it is structurally unbalanced to attach a heavy buckling restraint brace to the lightweight wooden beams and columns that make up a wooden house.

[0005] Therefore, a buckling restrained brace has been proposed that is suitable for use in the framework of wooden buildings such as wooden houses. Specifically, this is a buckling restrained brace that has a core material and a pair of restraining members arranged along both sides of the core material, in which the core material is made of steel and the pair of restraining members are made of wood, and laminated lumber is used for the restraining members, with the laminated lumber having lamina stacked parallel to the core material (for example, see Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 4901491 Summary of the Invention [Problem to be solved by the invention]

[0007] The wooden restraint material surrounding the steel core material that forms the buckling restrained brace is composed of a pair of restraining plates that face the two wide surfaces of the core material and a pair of side plates that connect the ends of the pair of restraining plates, but there is a problem with the buckling restrained brace that, for example, when the frame and the buckling restrained brace incorporated in the frame are significantly deformed outwardly during a major earthquake, the core material presses in the restraining plates, and the restraining plates pressed into the core material pull the side plates, causing cracks in the side plates. Patent Document 1 does not mention measures to prevent cracks in the side plates caused by the restraining plates pressed into the core material pulling the side plates when the buckling restrained brace is deformed outwardly.

[0008] The present invention has been made in consideration of the above-mentioned problems, and has an object to provide a buckling restrained brace that is suitable for use in a wooden building or the like and that can prevent the frame and buckling restrained brace from deforming outside the structural plane during a major earthquake, for example, and prevent cracks from occurring in the side panels pulled by the restraining plates as the core material forming the buckling restrained brace pushes into the restraining plates that form the wooden restraining material. [Means for solving the problem]

[0009] 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 wooden restraining plates arranged to face the two wide surfaces of the core material, and a pair of wooden side panels arranged to face the two narrow surfaces of the core material and connected to the pair of restraining plates; The end of the restraint plate is provided with a non-contact groove that does not come into contact with the wide surface of the core material, The area of ​​the restraint plate other than the non-contact groove is in contact with the wide surface of the core material.

[0010] According to this aspect, the end of the restraint plate is provided with a non-contact groove that does not come into contact with the wide surface of the core material, and the area of ​​the restraint plate other than the non-contact groove is in contact with the wide surface of the core material, so that when the frame and the buckling restraint brace are deformed outwardly of the structural plane, the non-contact groove is provided at the end of the restraint plate that receives the strongest pushing force from the core material, thereby eliminating or mitigating the contact between the core material and the restraint plate, and making it possible to suppress cracks that may occur at the end of the side plate connected to the position corresponding to the end of the restraint plate. Here, at each end of a pair of restraint plates facing the two wide surfaces of the core material, a non-contact groove is provided in the area where the core material can come into contact with the restraint plate when the buckling restraint brace is deformed outwardly of the structural plane.

[0011] The non-contact grooves at the ends of the restraint plate eliminate or reduce (prevent strong contact) the contact between the ends of the restraint plate and the core material, while the areas of the restraint plate other than the non-contact grooves abut the core material, ensuring that the restraint plate prevents the core material from buckling.

[0012] In this embodiment, a pair of restraining plates are connected to each other by a pair of side plates to form a wooden restraining member having a closed structure with four face members, and the steel core member is surrounded by the wooden restraining member. With this configuration, even if the buckling restrained brace of this embodiment is applied to the frame of a wooden building, there is no risk of it giving an out-of-match appearance to the frame components. Here, the wooden restraining member and the side plates may be made of solid wood or may be made of laminated wood with laminated lamina.

[0013] Furthermore, in this embodiment, the wooden restraint material has a configuration in which a pair of side plates are connected to a pair of restraining plates, which makes it easy to process the wooden restraint material. For example, the buckling restrained brace described in Patent Document 1 requires processing laminated lumber to produce two wooden restraint materials with an L-shaped cross section, turning them upside down and connecting them with a core material sandwiched between them. In contrast, the buckling restrained brace of this embodiment can be produced by connecting a pair of side plates to a pair of restraining plates to produce the wooden restraint material, and for example, inserting a core material into the hollow of this wooden restraint material to produce the buckling restrained brace. This makes it even easier to produce the buckling restrained brace.

[0014] In another aspect of the buckling restrained brace according to the present invention, The core material has a narrow portion at a center side in a longitudinal direction where the width of the wide surface is relatively narrow, and has a wide portion at an end side in the longitudinal direction where the width of the wide surface is relatively wide, The non-contact groove is characterized in that it extends from an edge of the restraint plate to a position corresponding to the boundary between the wide portion and the narrow portion of the core material.

[0015] According to this aspect, the core material has a narrow portion at the center in the longitudinal direction where the width of the wide surface is relatively narrow, and a wide portion at the end in the longitudinal direction where the width of the wide surface is relatively wide, so that the narrow portion at the center can be made into a region that is easily plasticized, and further, the plasticization region can be limited to the narrow portion at the center. In addition, since the boundary region between the wide portion and the narrow portion is a change region where the planar area and cross-sectional area of ​​the core material change, the additional bending moment acting on the core material can be absorbed in this change region. The additional bending moment (or simply, additional bending) is a bending moment that can act on the wooden restraint material due to the deformation when the frame and the buckling restraint brace are significantly deformed during a large earthquake, for example. In this way, in this aspect, the additional bending moment acting on the core material can be effectively absorbed in the boundary region between the wide portion and the narrow portion of the core material.

[0016] While the core material has a wide portion and a narrow portion, the restraint plate has a non-contact groove extending from its edge to a position corresponding to the boundary between the wide portion and the narrow portion of the core material, thereby making it possible to eliminate with a high degree of certainty the contact (pushing) of the core material against the end of the restraint plate.

[0017] In another aspect of the buckling restrained brace according to the present invention, a steel plate receiving groove is provided in an inner surface of the side plate in a corresponding range corresponding to the non-contact groove between the pair of restraining plates, A reinforcing steel plate spanning each side surface of the pair of restraint plates is fixed to each side surface of the pair of restraint plates, The reinforcing steel plate is accommodated in the steel plate accommodating groove without contacting the inner wall surface of the steel plate accommodating groove.

[0018] According to this aspect, a steel plate accommodation groove is provided in a corresponding range between the pair of restraining plates on the inner surface of the side plate, and the reinforcing steel plate fixed to each of the pair of restraining plates across the respective side surfaces of the pair of restraining plates is accommodated in the steel plate accommodation groove without contacting the inner wall surface of the steel plate accommodation groove. This allows the reinforcing steel plate fixed to the restraining plate and not in contact with the side plate to effectively resist pulling from the side plate. This, together with the non-contact groove provided at the end of the restraining plate, makes it possible to more effectively suppress cracks that may occur in the side plate. In addition, since the reinforcing steel plate does not contact the inner wall surface of the steel plate accommodation groove, there is no risk that the reinforcing steel plate will press the side plate and induce cracks.

[0019] In another aspect of the buckling restrained brace according to the present invention, The side plate has a fiber direction in a corresponding range that corresponds to the non-contact groove of the restraint plate, the fiber direction being in the short direction of the side plate, and the fiber direction outside the corresponding range being in the long direction of the side plate.

[0020] According to this aspect, the fiber direction of the corresponding range of the side panel that corresponds to the non-contact groove of the restraining plate is the short side direction of the side panel, so that the fiber direction in which the strength of the wood is high is oriented along (or to some extent along) the direction of cracks that may occur in the side panel due to tension from the restraining plate (the short side direction of the side panel), and the side panel can have high resistance to cracks. On the other hand, the fiber direction of the side panel other than the corresponding range of the end is oriented along the longitudinal direction of the side panel, so that the fiber direction in which the strength of the wood is high is oriented in the central part of the side panel where bending, etc. is prominent, and therefore the bending strength of the central part can be high.

[0021] In another aspect of the buckling restrained brace according to the present invention, The side plates are characterized in that piercing means extending toward the pair of restraining plates are pierced into corresponding areas of the side plates that correspond to the non-contact grooves of the restraining plates.

[0022] According to this aspect, the side plates are pierced by the piercing means extending toward the pair of restraining plates in the corresponding ranges of the side plates that correspond to the non-contact grooves of the restraining plates, more specifically, the piercing means is pierced in the direction along (or to a certain extent along) the direction of cracks that may occur in the side plates due to tension from the restraining plates (the short side direction of the side plates), so that the piercing means can resist cracks with high resistance. Here, examples of the piercing means include screws, nails, bolts including lag screw bolts, and the like.

[0023] In another aspect of the buckling restrained brace according to the present invention, First bolt holes are formed at corresponding positions of the pair of restraint plates, and a first bolt hole unit is formed by the corresponding first bolt holes, and a first long bolt is inserted into each of the first bolt hole units and fastened with a nut, Second bolt holes are opened at corresponding positions of the pair of side plates and the restraint plate, a second bolt hole unit is formed by the corresponding second bolt holes, and a second long bolt is inserted into each of the multiple second bolt hole units and tightened with a nut.

[0024] According to this aspect, the pair of restraining plates are joined by tightening nuts on the multiple first long bolts, and the pair of side plates are joined by tightening nuts on the multiple second long bolts together with the restraining plate therebetween, so that a wooden restraining member having high restraint properties for the pair of restraining plates and the pair of side plates can be formed. This makes it possible to form a buckling restrained brace having a highly rigid wooden restraining member that is unlikely to break due to an additional bending moment that may act.

[0025] In another aspect of the buckling restrained brace according to the present invention, The contact surfaces of the restraint plate and the side plate are joined with an adhesive and fastened by the second long bolts.

[0026] According to this aspect, the abutment surfaces of the restraint plate and the side plate are joined with an adhesive and further tightened with the second long bolt, so that the adhesive surfaces that are the abutment surfaces of the restraint plate and the side plate are crimped with the second long bolt, thereby forming a buckling restraint brace with wooden restraint material having even higher connection strength between the restraint plate and the side plate.

[0027] In another aspect of the buckling restrained brace according to the present invention, A reinforcing rib is joined to the wide surface at the end of the longitudinal direction of the core material so as to be perpendicular to the wide surface, forming a cross-shaped cross section; The wooden restraint material is characterized in that a slit is provided at a position corresponding to the reinforcing rib so as not to interfere with the reinforcing rib.

[0028] According to this aspect, the longitudinal end of the core material has a cross-shaped cross section due to the joining of the reinforcing ribs perpendicular to the wide surface of the core material, so that when the buckling restrained brace is attached to the gusset plate so that the wide surface of the core material is arranged parallel to the structural surface of the building, the core material has a reinforcing rib perpendicular to the wide surface parallel to the structural surface, so that the rigidity of the end of the core material in the direction outward from the structural surface can be increased. In the gusset plate of the structural surface to which the core material with a cross-shaped cross section is attached, a fin stiffener is attached to the gusset plate, and the core material and the gusset plate, and the reinforcing rib and the fin stiffener of the buckling restrained brace are joined by high tension bolts or the like via splice plates. In this aspect, slits are provided at positions corresponding to the reinforcing ribs of the wooden restraining material, and the slits are configured to prevent interference between the wooden restraining material and the reinforcing ribs.

[0029] Another aspect of the buckling restraint brace according to the present invention is In a plan view, a gap is provided between the slit and the reinforcing rib.

[0030] According to this embodiment, the gap between the slit and the reinforcing rib can absorb the expansion and contraction of the core material when it expands and contracts in response to the deformation of the structural surface, and the problem of the expanding and contracting core material contacting the wall surface of the slit and causing damage to the wooden restraint material can be eliminated. Here, the setting of this gap is also left to the discretion of the designer, and the amount of expansion and contraction of the core material is calculated based on the set inter-story deformation angle, and for example, the gap is set to be equal to or larger than the amount of expansion and contraction of the core material. Note that the "gap" here includes the gap between the longitudinal end of the slit and the reinforcing rib as well as the gap between the side surface of the slit and the reinforcing rib, and the gap between the side surface of the slit and the reinforcing rib can be set to the same gap as the gap between the side surface of the wide part of the core material and the side plate described above. In addition, a separate gap is formed between the core material and the restraint plate due to the non-contact groove provided in the restraint plate, and this gap is also set to a size such that the core material does not strongly press or come into contact with the restraint plate when the buckling restraint brace is deformed during a large earthquake.

[0031] In addition, another aspect of the buckling restraint brace according to this aspect is as follows: The present invention is characterized in that an insert plate is interposed between the broad surface of the core material and the restraining plate.

[0032] According to this embodiment, the core material undergoes high-order buckling deformation, which causes a localized compressive force to act on the restraining plate, and the restraining plate is prevented from being damaged by this localized force. By interposing the inner plate between the wide surface of the core material and the restraining plate, the force acting from the convex portion of the high-order buckling deformation of the core material is first transmitted to the inner plate, which then spreads within the inner plate, and the force diffused within the inner plate acts on the wooden restraining plate. This effectively prevents the wooden restraining plate from being damaged by multiple localized forces acting from the core material. Effect of the Invention

[0033] As can be understood from the above explanation, the buckling restraint brace of the present invention is suitable for use within the framework of a wooden building or the like. For example, during a major earthquake, the framework and buckling restraint brace can be deformed outside the structural plane, and the core material that forms the buckling restraint brace can push into the restraining plates that form the wooden restraining material, preventing cracks from occurring in the side panels that are pulled by the restraining plates. [Brief description of the drawings]

[0034] [Figure 1] FIG. 2 is a perspective view showing an example of a core material that forms the buckling restraint brace according to the first embodiment, together with a spacer. [Diagram 2] FIG. 2 is a perspective view of an example of a wooden restraint member that forms the buckling restraint brace according to the first embodiment. [Diagram 3] FIG. 2 is a perspective view of an example of a buckling restraint brace according to the first embodiment. [Figure 4] 4 is a view taken in the direction of the arrow IV in FIG. 3. [Diagram 5] FIG. 4 is a view taken along the arrows VV in FIG. 3. [Figure 6] FIG. 6 is a view taken along the line VI-VI in FIG. [Figure 7] FIG. 7 is a view taken along the line VII-VII of FIG. 3. [Figure 8] FIG. 8 is a view taken along the line VIII-VIII in FIG. [Figure 9] FIG. 11 is a perspective view showing a first modified example of a wooden restraint material. [Figure 10] FIG. 11 is a perspective view showing a second modified example of the wooden restraint material. [Figure 11] FIG. 11 is a perspective view showing a third modified example of a wooden restraining material. [Figure 12] FIG. 2 is a diagram showing the state in which the buckling restraint brace according to the first embodiment is incorporated into the frame of a wooden building or the like. [Figure 13] FIG. 1 is a diagram illustrating the deformation of the frame during a large earthquake and the additional bending moment at the buckling-restrained brace joint caused by the deformation of the frame. [Figure 14] FIG. 11 is a perspective view showing an example of a core material that forms a buckling restraint brace according to a second embodiment, together with a spacer. [Figure 15] FIG. 11 is a longitudinal cross-sectional view of an example of a buckling restraint brace according to a second embodiment. [Figure 16] 16 is an enlarged view of a portion XVI in FIG. 15, illustrating how a force acting locally from a convex portion on the surface of the core material is diffused via the insertion plate and transmitted to the restraint plate. FIG. [Figure 17] FIG. 13 is a diagram showing the overall buckling line of the buckling restraint brace. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] Hereinafter, the buckling restraint brace according to each embodiment will be described with reference to the accompanying drawings. In this specification and the drawings, substantially the same components are designated by the same reference numerals to avoid redundant description.

[0036] [Buckling restrained brace according to the first embodiment] <Core material> First, an example of a core material that forms the buckling restrained brace according to the first embodiment will be described with reference to Fig. 1. Here, Fig. 1 is a perspective view showing an example of a core material that forms the buckling restrained brace according to the first embodiment together with a spacer.

[0037] The core material 10 is formed from an elongated flat steel plate, and has a narrow portion 13 at the center in the longitudinal direction where the wide surface 11a is relatively narrow, and a wide portion 12 at the end in the longitudinal direction where the wide surface 11a is relatively wide. A reinforcing rib 14 perpendicular to the wide surface 11a is welded to the wide surface 11a at the end in the longitudinal direction of the core material 10, giving it a cross-shaped cross section.

[0038] Since the core material 10 has a narrow width portion 13 at the center of its longitudinal direction and a wide width portion 12 at the end of the longitudinal direction, the narrow width portion 13 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 13 at the center.

[0039] As described below, the wide portion 12 and the reinforcing rib 14 each have bolt holes 12a, 14a for bolting via a splice plate to a gusset plate provided on the structural surface or a fin stiffener (see FIG. 11) attached to the gusset plate. When the buckling restrained brace 100 is attached to the gusset plate so that the wide surface 11a of the core material 10 is arranged parallel to the structural surface of the building, the core material 10 has reinforcing ribs 14 that are perpendicular to the wide surface 11a that is parallel to the structural surface, thereby increasing the rigidity of the end of the core material 10 in the direction outside the structural surface.

[0040] The core material 10 is preferably formed from a steel material with a low yield point, such as SN material (rolled steel material for architectural structures) or LYP material (very low yield point steel material), and the yield of the core material 10 improves the earthquake energy absorption.

[0041] At the center position of narrow portion 13 of core material 10, cylindrical steel protrusions 15 protrude from the left and right side surfaces of narrow portion 13 (one example of the peripheral surface of narrow portion 13). Protrusions 15 are joined to the side surfaces of narrow portion 13 by welding or the like. These protrusions 15 engage with engagement holes formed in a wooden restraining material (see FIG. 2) described below. Note that protrusions 15 may protrude from the upper and lower planes of narrow portion 13, in which case engagement holes are formed at corresponding positions of restraining plates 21 in the wooden restraining material (see FIG. 2) and protrusions 15 engage with these engagement holes.

[0042] Thin rectangular columnar spacers 16 are disposed in the X1 direction on both left and right sides of the narrow portion 13, and the core material 10 is housed inside a wooden restraining material described below with the spacers 16 disposed on both left and right sides of the narrow portion 13. The spacer 16 may be either a steel member or a wooden member. The spacer 16 may also be in a shape other than that shown in the figure, such as a cylindrical shape. The spacer 16 has a plurality of bolt holes 16a (three in the illustrated example) spaced apart in the longitudinal direction, through which first long bolts described below are inserted.

[0043] <Wooden restraint material> Next, an example of a wooden restraining material that forms the buckling restrained brace according to the first embodiment will be described with reference to Fig. 2. Here, Fig. 2 is a perspective view of an example of a wooden restraining material that forms the buckling restrained brace according to the first embodiment.

[0044] The wooden restraining material 20 has a pair of restraining plates 21 and a pair of side plates 22 connecting the pair of restraining plates 21, and the core material 10 is arranged in a gap 25 between the pair of restraining plates 21. The pair of wooden restraining plates 21 are arranged so as to face two wide surfaces 11a (see FIG. 1) of the core material 10, and the pair of wooden side plates 22 connected to the pair of restraining plates 21 are arranged so as to face two narrow surfaces 11b (see FIG. 1) of the core material 10.

[0045] First bolt holes 21a each having a counterbore are opened at corresponding positions of the pair of restraint plates 21, and a first bolt hole unit 21b is formed by the two corresponding first bolt holes 21a. In the illustrated example, two first bolt hole units 21b are provided in the width direction of restraint plate 21 and six are provided in the longitudinal direction of restraint plate 21, for a total of twelve first bolt hole units 21b.

[0046] When core material 10 is disposed in gap 25 between a pair of restraining plates 21, each bolt hole 16a opened in spacer 16 is positioned at a position corresponding to each first bolt hole unit 21b, and bolt hole 16a also forms first bolt hole unit 21b. A first long bolt 31 is inserted into first bolt hole unit 21b and tightened with a nut 33. More specifically, a washer 32 is disposed in the counterbore of one of first bolt holes 21a forming first bolt hole unit 21b, first long bolt 31 is inserted into first bolt hole unit 21b via washer 32, a washer 34 is disposed in the counterbore of the other first bolt hole 21a, and a nut 33 is tightened into the thread groove at the tip of first long bolt 31 protruding outward from washer 34.

[0047] Meanwhile, second bolt holes 22a, 21c are opened at corresponding positions of the pair of side plates 22 and restraint plate 21, respectively, and second bolt hole unit 22b is formed by corresponding second bolt holes 22a, 21c. Second bolt hole unit 22b is provided at a position that does not interfere with first bolt hole unit 21b, and in the illustrated example, two are provided in the width direction of side plate 22 and seven are provided in the longitudinal direction of side plate 22, for a total of fourteen second bolt hole units 22a, 21c.

[0048] A second-long bolt 41 is inserted into each second bolt hole unit 22b and tightened with a nut 43. More specifically, a washer 42 is disposed in the counterbore of one of the second bolt holes 22a that form the second bolt hole unit 22b, the second-long bolt 41 is inserted into the second bolt hole unit 22b via the washer 42, a washer 44 is disposed in the counterbore of the other second bolt hole 22a, and a nut 43 is tightened into the thread groove at the tip of the second-long bolt 41 that protrudes outward from the washer 44.

[0049] In addition, when tightening the second long bolt 41 with the nut 43, adhesive is applied to the contact surfaces of the restraint plate 21 and the side plate 22, and the second long bolt 41 is tightened with the nut 43 before the adhesive hardens.

[0050] Here, the adhesive may be a urethane-based adhesive or an epoxy-based adhesive, but it is preferable to use a urethane-based adhesive that takes a certain amount of time to harden (for example, about 24 hours) so that after the adhesive is applied to the contact surfaces of restraint plate 21 and side plate 22, second-long bolt 41 can be tightened with nut 43 before the adhesive hardens. The adhesive surface formed by the hardening of the adhesive is firmly compressed by the tightening force applied when second-long bolt 41 is tightened with nut 43.

[0051] In this way, a pair of restraint plates 21 are restrained together by tightening multiple first long bolts 31 with nuts 33, and a pair of side plates 22 and the restraint plate 21 are restrained by tightening second long bolts 41 with nuts 43 via the adhesive surfaces, thereby forming a wooden restraint material 20 with a closed structure in which the restraint plates 21 and side plates 22 are firmly joined.

[0052] When high joint strength as in the illustrated example is not required, the wooden restraining member 20 may be formed by bonding a pair of restraining plates 21 and a pair of side plates 22 together using only an adhesive.

[0053] The left and right side panels 22 have engagement holes 22c at their longitudinal center positions into which the protrusions 15 of the core material 10 engage. The protrusions 15 of the core material 10 engage with the engagement holes 22c formed in the wooden restraining material 20, thereby preventing the core material 10 inserted inside the wooden restraining material 20 from biasing toward one end of the wooden restraining material 20. Therefore, when the core material 10 biases toward one end of the wooden restraining material 20 in this way, the other end of the wooden restraining material 20 where the core material 10 is not present does not become a weak part in terms of strength.

[0054] Furthermore, the spacer 16 has bolt holes 16a constituting the first bolt hole unit 21b, and the first long bolts 31 are inserted into the bolt holes 16a, thereby preventing the spacer 16 from moving in the longitudinal direction of the core material 10. As will be described below with reference to FIG. 11, since the buckling restrained brace is generally arranged in a diagonal direction on the structural surface, the spacer 16 is likely to move diagonally downward, and this movement of the spacer 16 tends to cause a large gap between the end of the spacer 16 and the wide portion 12 of the core material 10 diagonally upward. Therefore, the diagonally upward region of the buckling restrained brace where the spacer 16 does not exist is likely to become a weak portion in terms of strength, but by inserting the first long bolts 31 into the bolt holes 16a of the spacer 16 as shown in the figure, such movement of the spacer 16 is eliminated, and no weak portion in terms of strength caused by the movement of the spacer 16 occurs.

[0055] In addition, non-contact grooves 23 that do not come into contact with the wide surface 11a of the core material 10 housed in the gap 25 are provided at both ends of the restraint plate 21, and the area of ​​the restraint plate 21 other than the non-contact grooves 23 (the area on the central side) comes into contact with the wide surface 11a of the core material 10. This configuration and the effects achieved by this configuration will be described in detail below.

[0056] The restraining plate 21 and the side plate 22 may be made of either solid wood or wood materials including laminated wood in which laminas are stacked. As described in detail below, the cross-sectional area, cross-sectional rigidity, Young's modulus, etc. of the wooden restraining member 20 are set so as to prevent the buckling restrained brace from buckling as a whole. This Young's modulus is determined by the material of the wood. Examples of the material of the wood include Japanese cypress, red pine, larch, fir, and Yezo spruce.

[0057] At the end of the restraint plate 21, a slit 24 that does not interfere with the reinforcing rib 14 is provided at a position that corresponds to the reinforcing rib 14 when the core material 10 is accommodated in the gap 25.

[0058] <Buckling restraint brace> Next, an example of a buckling restrained brace according to the first embodiment, formed from the core material 10 and wooden restraining material 20 described above, will be described with reference to Figures 3 to 11. Here, Figure 3 is a perspective view of an example of a buckling restrained brace according to the first embodiment. Also, Figures 4, 5, 6, 7, and 8 are a view taken in the direction of arrow IV in Figure 3, a view taken in the direction of arrow VV in Figure 3, a view taken in the direction of arrow VI-VI in Figure 3, a view taken in the direction of arrow VII-VII in Figure 3, and a view taken in the direction of arrow VIII-VIII in Figure 3, respectively.

[0059] The buckling restraint brace 100 is constructed such that wooden restraint materials 20 are arranged to surround the narrow width portion 13 and part of the wide width portion 12 of the core material 10, and the cross-shaped portion of the end of the wide width portion 12 protrudes from the end of the wooden restraint material 20, and the bolt holes 12a, 14a of the wide width portion 12 and the reinforcing rib 14 that protrude outward face the outside.

[0060] A core material 10 is disposed in the gap 25 between a pair of restraint plates 21, a plurality of first long bolts 31 are inserted through the pair of restraint plates 21 and spacers 16 and fastened with nuts 33, and second long bolts 41 are inserted through the pair of side plates 22 and restraint plates 21 and fastened with nuts 43 to form a buckling restraint brace 100. As shown in the figure, the extension direction of the first long bolts 31 is the weak axis direction of the core material 10, and the extension direction of the second long bolts 41 is the strong axis direction of the core material 10.

[0061] The buckling restrained brace 100 has a configuration in which the core material 10 is surrounded by the wooden restraining material 20 formed by tightly fastening a pair of restraining plates 21 and a pair of side plates 22 by nuts fastening a plurality of first long bolts 31 and second long bolts 41, resulting in a buckling restrained brace with high buckling strength. Furthermore, because the steel core material 10 is surrounded by the wooden restraining material 20, even when the buckling restrained brace 100 is applied to the frame of a wooden building, it does not give an appearance that is out of proportion to the frame constituent members.

[0062] In the buckling restraint brace 100 shown in the figure, the core material 10 is accommodated within the gap 25 of the wooden restraint material 20 with spacers 16 arranged on the left and right sides of the narrow width portion 13, and the protrusions 15 extending laterally from the sides of the narrow width portion 13 are engaged with the engagement holes 22c.

[0063] Between the side surface of the wide portion 12 of the core material 10 and the side plate 22 of the wooden restraint material 20, a gap G1 of width t1 is provided.

[0064] Furthermore, a non-contact groove 23 is formed at the end of the restraint plate 21 so that the restraint plate 21 does not come into contact with the wide portion 12 of the core material 10, and a gap G3 of height t2 is provided between the non-contact groove 23 and the wide portion 12. As shown in detail in Fig. 7, this non-contact groove 23 is provided in a range from the edge of the restraint plate 21 to a position corresponding to the additional bending absorption area A of the core material 10 (boundary region A between the wide portion 12 and the narrow portion 13).

[0065] 7 and 8, boundary region A between wide portion 12 and narrow portion 13 is a transition region where the planar area and cross-sectional area of ​​core material 10 change, and therefore serves as an additional bending absorption area where the additional bending moment acting on core material 10 can be absorbed in this transition region. In this way, the additional bending moment acting on core material 10 is effectively absorbed in boundary region A between wide portion 12 and narrow portion 13 of core material 10, and gap G1 provided between core material 10 and side plate 22 of wooden restraint member 20 prevents the additional bending moment acting on core material 10 from acting on side plate 22 of wooden restraint member 20.

[0066] Furthermore, between the reinforcing rib 14 and the slit 24 of the restraining plate 21 of the wooden restraining member 20, a gap G2 of width t3 in the longitudinal direction of the reinforcing rib 14 and width t1 is provided on the side of the reinforcing rib 14. In this way, by providing the gap G1 between the side surface of the wide portion 12 and the side plate 22 of the wooden restraining member 20, when the structural surface to which the buckling restrained brace 100 is attached is significantly deformed, this gap G1 absorbs the deformation of the core material 10, and prevents so-called additional bending moment from acting on the wooden restraining member 20. On the other hand, by providing the gap G2 between the slit 24 and the reinforcing rib 14, when the core material 10 expands and contracts in response to the deformation of the structural surface, this gap G2 can absorb the expansion and contraction of the core material 10, and this can eliminate the problem that the expanding and contracting core material 10 comes into contact with the wall surface of the slit 24, causing the wooden restraining member 20 to be damaged.

[0067] 4 and 5, in the buckling restrained brace 100, non-contact grooves 23 are provided in the restraining plate 21 over the range from its edge to a position corresponding to the additional bending absorption area A of the core material 10. Meanwhile, as shown in Fig. 6, the area of ​​the restraining plate 21 other than the non-contact grooves 23 is in contact with the narrow portion 13 of the core material 10.

[0068] With the above configuration, when the frame S (see Figure 11) and the buckling restraint brace 100 are deformed outside the structural plane, the non-contact groove 23 eliminates or reduces contact between the core material 10 and the restraint plate 21 at the end of the restraint plate 21 which may receive the strongest pushing force from the core material 10 (prevents strong contact).

[0069] In this way, the pressing of the core material 10 against the restraint plate 21 is eliminated or alleviated, thereby making it possible to suppress cracks that may occur at the ends of the side plates 22 that are connected at positions corresponding to the ends of the restraint plates 21. Here, when the restraint plate 21 is pressed from the core material 10, cracks that occur in the side plates 22 due to tension from the pressed-in restraint plate 21 tend to occur significantly in the short direction or a direction close to the short direction in the longitudinal section of the wooden restraint material 20 as shown in Figures 4 and 5, but this cracking is effectively eliminated.

[0070] In addition, the non-contact groove 23 at the end of the restraint plate 21 eliminates or reduces the contact between the end of the restraint plate 21 and the core material 10, while the area of ​​the restraint plate 21 other than the non-contact groove 23 (the area toward the center) abuts against the core material 10, thereby ensuring the ability of the restraint plate 21 to prevent buckling of the core material 10.

[0071] 7 and 8, by providing narrow portion 13 at the center of core material 10, a relatively large gap G4 (larger than gap G1 between wide portion 12 at the end of core material 10 and side plate 22) exists between narrow portion 13 and side plate 22. By interposing spacer 16 in gap G4 to close gap G4, it is possible to prevent buckling in the strong axis direction of core material 10 (direction parallel to wide surface 11a of core material 10). Therefore, overall buckling of buckling restrained brace 100 is suppressed and the compressive strength of buckling restrained brace 100 is improved, thereby providing an excellent seismic reinforcement effect to a frame incorporating buckling restrained brace 100 and a building including this frame.

[0072] Next, first to third modified examples of the wooden restraining material that forms the buckling restrained brace 100 will be described with reference to Figures 9 to 11. Each modified example of the wooden restraining material has a distinctive feature in its side panels.

[0073] First, the wooden restraint material 20A shown in Figure 9 has a side panel 22A that has a central side panel 26 and end side panels 27 at both ends of the central side panel 26, and the central side panel 26 and the end side panels 27 are connected by an adhesive or the like.

[0074] The end side plate 27 is in a range corresponding to the non-contact groove 23 of the restraint plate 21, and the grain direction of the wood of the end side plate 27 is oriented in the short direction of the side plate 22A. On the other hand, the grain direction of the wood of the central side plate 26 is arranged in the longitudinal direction of the side plate 22A.

[0075] In this way, the fiber direction of the end side plate 27 in the corresponding range corresponding to the non-contact groove 23 of the restraining plate 21 is the short side direction of the side plate 22A, so that the fiber direction in which the strength of the wood is high is oriented along (or to some extent along) the direction of cracks that may occur in the end side plate 27 due to tension from the restraining plate 21 (the short side direction of the side plate 22A), and therefore the end side plate 27 can resist cracks with high resistance. On the other hand, the fiber direction of the central side plate 26 outside the corresponding range of the end among the side plates 22A is oriented along the longitudinal direction of the central side plate 26, so that the fiber direction in which the strength of the wood is high is oriented in the central part of the side plate 22A where bending, etc., is prominent, and therefore the bending strength of the central part can be high.

[0076] 10, a wooden restraining material 20B is pierced with a plurality of piercing means 28 (three in the illustrated example) extending toward the pair of restraining plates (in the short direction of the side plates 22B) in a range of the side plates 22B that corresponds to the non-contact grooves 23 of the restraining plates 21. Here, the piercing means 28 include screws, nails, bolts including lag screw bolts, etc.

[0077] In this way, the piercing means 28 extending toward the pair of restraining plates pierces the side plate 22B in a corresponding range corresponding to the non-contact groove 23 of the restraining plate 21, and more specifically, the piercing means 28 pierces in a direction along (or to some extent along) the direction of cracks that may occur in the side plate 22B due to pulling from the restraining plate 21 (the short side direction of the side plate), so that the piercing means 28 can resist cracks with high resistance force.

[0078] 11, a wooden restraining material 20C is provided with a steel plate accommodating groove 22e that is rectangular in plan view as seen from the inside, in a corresponding range of the inner surface of a side plate 22C (the surface facing the non-contact groove 23) that corresponds to the non-contact groove 23 between the pair of restraining plates 21. A reinforcing steel plate 45 that is rectangular in plan view and spans each side surface is fixed to each side surface of the pair of restraining plates 21. For example, the reinforcing steel plate 45 is fixed to the side surfaces of the pair of restraining plates 21 by adhesive, drill screws, or both of these fixing means.

[0079] Here, the planar dimensions of the reinforcing steel plate 45 are set smaller than the planar dimensions of the steel plate accommodating groove 22e, and further, the thickness of the reinforcing steel plate 45 is set thinner than the groove depth of the steel plate accommodating groove 22e.

[0080] When a reinforcing steel plate 45 is fixed to the side surfaces of a pair of restraint plates 21 and the pair of restraint plates 21 and side plates 22 are connected so as to accommodate the reinforcing steel plate 45 in the steel plate accommodating groove 22e, the reinforcing steel plate 45, which has dimensions smaller than the planar dimensions and depth of the steel plate accommodating groove 22e, is accommodated in the steel plate accommodating groove 22e without contacting the inner wall surface of the steel plate accommodating groove 22e.

[0081] On the left and right sides of the pair of restraint plates 21, reinforcing steel plates 45 are accommodated in the steel plate accommodating groove 22e without contacting the side plates 22C, and the pair of side plates 22C are connected to the pair of restraint plates 21 to form the wooden restraint material 20C.

[0082] In this way, the reinforcing steel plate 45, which does not contact the side plate 22C, is fixed to the side surfaces of the pair of restraint plates 21, so that the reinforcing steel plate 45 can withstand with high resistance the pulling force from the side plate 22. At this time, because the reinforcing steel plate 45 does not contact the inner wall surface of the steel plate accommodating groove 22e, there is no risk that the reinforcing steel plate 45 will press against the side plate 22C and induce cracks.

[0083] In the wooden restraining materials 20A, 20B, 20C relating to the first to third modified examples, a pair of restraining plates 21 have non-contact grooves 23 at both ends that eliminate or reduce the pressure caused by the wide portion 12 of the deforming core material 10. In addition, the ends of the side plates 22A, 22B are reinforced against cracks by end side plates 27 in the fiber direction that runs along the crack direction, multiple piercing means 28, and reinforcing steel plates 45, so that cracks that may occur in the side plates 22A, 22B, 22C can be eliminated even more effectively.

[0084] <Example of application of buckling restraint braces to structures> Next, an example of application of the buckling restrained brace to a frame will be described with reference to Fig. 12 and Fig. 13. Fig. 12 is a diagram showing a state in which the buckling restrained brace according to the first embodiment is incorporated into the frame of a wooden building or the like. Fig. 13 is a diagram explaining the deformation of the frame during a major earthquake and the additional bending moment at the buckling restrained brace joint caused by the deformation of the frame. The buckling restrained brace in the illustrated example may be incorporated into the frame of a steel (S) building, a reinforced concrete (RC) building, or a steel reinforced concrete (SRC) building, in addition to the frame of a wooden building.

[0085] The frame S shown in Fig. 12 is formed of wooden columns C and beams B that constitute a wooden building or the like. Gusset plates GP made of flat steel are attached to the two diagonally positioned corners. Fin stiffeners FS are joined by welding to the surface of the gusset plates GP so as to be perpendicular to the surface. The fin stiffeners FS are joined to the gusset plates GP so that their cores L3 intersect with the intersection O between the column center L1 of the column C and the beam center L2 of the beam B. The buckling restraint brace 100 is also arranged in a line that passes through both of the intersections O in the diagonally positioned positions.

[0086] The gusset plate GP and the wide portion 12 of the core material 10 are joined by high tension bolts via a splice plate SP, and the fin stiffener FS and the reinforcing rib 14 are joined by high tension bolts via the splice plate SP.

[0087] As shown in Figure 13, when a large earthquake occurs, the structural plane is deformed, and in the buckling-restrained brace joint, if the joint is considered to be rigid, an additional bending moment shown in the following equation (1) can act on the joint.

[0088]

number

[0089] According to the buckling restrained brace 100, a gap G1 of width t1 is provided between the side surface of the wide portion 12 of the core material 10 and the side plate 22 of the wooden restraining member 20, so that when the structural surface to which the buckling restrained brace 100 is attached undergoes a large deformation, this gap G1 absorbs the deformation of the core material 10 and prevents additional bending moment from acting on the wooden restraining member 20. Furthermore, between the reinforcing rib 14 and the slit 24 of the restraining plate 21 of the wooden restraining member 20, a gap G2 of width t2 in the longitudinal direction of the reinforcing rib 14 and width t1 is provided on the side of the reinforcing rib 14, so that when the core material 10 expands and contracts in response to deformation of the structural surface, the gap G2 can absorb the expansion and contraction of the core material 10, eliminating the problem of the expanding and contracting core material 10 coming into contact with the wall surface of the slit 24 and causing the wooden restraining member 20 to be damaged. Furthermore, a gap G3 is formed by the non-contact groove 23 at the end of the restraint plate 21 which is likely to receive the strongest pushing force from the core material 10, and the gap G3 eliminates or reduces contact between the core material 10 and the restraint plate 21, thereby effectively suppressing cracks that may occur at the end of the side plate 22 connected at a position corresponding to the end of the restraint plate 21.

[0090] [Buckling restrained brace according to the second embodiment] Next, an example of a core material forming the buckling restrained brace according to the second embodiment will be described with reference to Fig. 14 to Fig. 16. Here, Fig. 14 is a perspective view showing an example of a core material forming the buckling restrained brace according to the second embodiment together with a spacer, and Fig. 15 is a vertical cross-sectional view of an example of the buckling restrained brace according to the second embodiment. Also, Fig. 16 is an enlarged view of part XVI in Fig. 15, which explains how a force acting locally from a convex part on the surface of the core material is diffused through an insertion plate and transmitted to the restraining plate.

[0091] The buckling restrained brace 100A differs from the buckling restrained brace 100 in that an insert plate 17 is interposed between the wide surface 11a of the core material 10 and the restraining plate 21. Either a steel plate or a wooden plate may be used as the insert plate 17, and the wooden plate may be, for example, LVL (Laminated Veneer Lumber). Note that, in this embodiment as well, the protrusions 15 may protrude from the upper and lower planes of the narrow portion 13.

[0092] In the wide surface of the inner plate 17, a slit 18 is formed at a position corresponding to the reinforcing rib 14 of the core material 10 at the end in the longitudinal direction so as not to interfere with the reinforcing rib 14. Also, in the inner plate 17, a bolt hole 17a is formed at a position corresponding to the bolt hole 16a formed in the spacer 16, and a first long bolt 31 shown in Fig. 2 is inserted therethrough.

[0093] According to the buckling restrained brace 100A, as shown in FIG. 16, a compressive force P acts locally on the restraining plate 21 from the core material 10 due to the high-order buckling deformation of the core material 10, and damage to the restraining plate 21 due to this local force can be suppressed. The action of the local force P in this way can lead to damage to the wooden restraining plate 21. Therefore, by interposing the inner plate 17 between the wide surface 11a of the core material 10 and the restraining plate 21, the force P acting from the convex portion 10a of the high-order buckling deformation of the core material 10 is first transmitted to the inner plate 17, the transmitted force P spreads within the inner plate 17, and the force diffused within the inner plate 17 acts on the wooden restraining plate 21 as a distributed force q. This effectively suppresses damage to the wooden restraining plate 21 due to multiple local forces P acting from the core material 10.

[0094] [Consideration of overall buckling] Next, we will explain the design method for preventing global buckling of the buckling restrained brace.

[0095] When designing a buckling restrained brace, it is designed to satisfy the following equation (2) so that global buckling of the buckling restrained brace does not occur.

[0096]

number

[0097] Here, the bending moment acting on the center of the restraint plate can be expressed by the following equation (3).

[0098]

number

[0099] The condition for preventing the overall buckling of the wooden restraint member is to satisfy the following equation (4).

[0100]

number

[0101] Equation (4) is shown in Figure 17 as the global bending stress line of the buckling restrained brace. In Figure 17, the upper side of the global bending stress line is the safe zone, and the lower side is the dangerous zone, and the design axial force of the wooden restraint member, Euler load, length of the general part of the core material, and yield bending strength of the wooden restraint member are set so as to fall within the safe zone. Note that the global bending stress line of the buckling restrained brace shown in Figure 17 applies to both global buckling in the weak axis direction and global buckling in the strong axis direction of the core material.

[0102] In addition to examining the relationship between the yield bending strength of the wooden restraint material and the bending moment acting on it as described above, it is also advisable to examine that the short-term allowable bending strength of the wooden restraint material will be greater than the bending moment acting on it when the core material yields (formula omitted).

[0103] <Study on the compressive failure of wooden restraint material> Next, we will explain how to evaluate the embedding failure of wooden restraints. To prevent the wooden restraints from being broken due to the core material embedding into them, we verify that the following formula (5) is satisfied.

[0104]

number

[0105] In addition to examining the relationship between the compressive strength of the restraint plate and the stiffening force acting as described above, it is also advisable to check that the short-term allowable compressive strength of the restraint plate will be greater than the stiffening force acting at the time of core material yielding (formula omitted).

[0106] <Specifications for the first long bolt (weak axis direction bolt) and the second long bolt (strong axis direction bolt)> Next, a method for setting the specifications of the first long bolts (weak axis direction bolts) and the second long bolts (strong axis direction bolts) will be described.

[0107] When setting the specifications for the first long bolts (weak axis direction bolts) and second long bolts (strong axis direction bolts), the sum of the yield strengths of each long bolt shall be set to be greater than or equal to the sum of the reinforcing forces acting on the wooden restraint material, and the specifications of each long bolt (yield stress, number of first and second long bolts, effective cross-sectional area (effective cross-sectional area per bolt and total effective cross-sectional area based on the number of bolts), etc.) shall be determined so as to satisfy the following formula (6).

[0108]

number

[0109] 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]

[0110] 10: Core material 11a: Wide surface 11b:Narrow side 12: Wide section 12a: Bolt hole 13: Narrow section 14: Reinforcement rib 14a: Bolt hole 15: Protrusion 16: Spacer 16a: Bolt hole 17: Interpolation board 17a: Bolt hole 20, 20A, 20B, 20C: Wooden restraints 21: Restraint plate 21a: First bolt hole 21b: First bolt hole unit 21c: Second bolt hole 22,22A,22B,22C: Side plate 22a: Second bolt hole 22b: Second bolt hole unit 22c: Engagement hole 22d: Steel plate receiving groove 23: Non-contact groove 24: Slit 25: Gap 26: Center side panel 27: End side plate 28: Piercing method 31: First long bolt 32: Washer 33: Nut 34: Washer 41: Second long bolt 42: Washer 43: Nut 44: Washer 45: Steel plate for reinforcement 100,100A: Buckling restraint brace G1, G2, G3, G4, G5: Gap A: Additional bending absorption area (boundary area) S: Frame (composition) C: Pillar B: Beam GP: Gusset plate FS: Fin stiffener SP: Splice plate

Claims

1. A steel plate-shaped core material, a pair of wooden restraining plates arranged to face the two wide surfaces of the core material, and a pair of wooden side panels arranged to face the two narrow surfaces of the core material and connected to the pair of restraining plates; The end of the restraint plate is provided with a non-contact groove that does not come into contact with the wide surface of the core material, an area of ​​the restraint plate other than the non-contact groove and the wide surface of the core material are in contact with each other; The core material has a narrow portion at a center side in a longitudinal direction where the width of the wide surface is relatively narrow, and has a wide portion at an end side in the longitudinal direction where the width of the wide surface is relatively wide, A buckling restraint brace, characterized in that the non-contact groove extends from an edge of the restraint plate to a position corresponding to the boundary between the wide portion and the narrow portion of the core material.

2. a steel plate receiving groove is provided in an inner surface of the side plate in a corresponding range corresponding to the non-contact groove between the pair of restraining plates, A reinforcing steel plate spanning each side surface of the pair of restraint plates is fixed to each side surface of the pair of restraint plates, 2. The buckling restraint brace according to claim 1, wherein the reinforcing steel plate is accommodated in the steel plate accommodation groove without contacting an inner wall surface of the steel plate accommodation groove.

3. 2. The buckling restraint brace of claim 1, wherein the fiber direction of the corresponding range of the side panel that corresponds to the non-contact groove of the restraint plate is the short direction of the side panel, and the fiber direction outside of the corresponding range is the long direction of the side panel.

4. The buckling restraint brace according to claim 1, characterized in that the side plates are pierced in corresponding areas of the non-contact grooves of the restraint plates with piercing means extending toward the pair of restraint plates.

5. First bolt holes are formed at corresponding positions of the pair of restraint plates, and a first bolt hole unit is formed by the corresponding first bolt holes, and a first long bolt is inserted into each of the first bolt hole units and fastened with a nut, 5. A buckling restraint brace as described in any one of claims 1 to 4, characterized in that second bolt holes are opened at corresponding positions of the pair of side plates and the restraint plate, a second bolt hole unit is formed by the corresponding second bolt holes, and a second long bolt is inserted into each of the multiple second bolt hole units and tightened with a nut.

6. 6. The buckling restraint brace according to claim 5, wherein the abutting surfaces of the restraint plate and the side plate are joined with an adhesive and fastened by the second long bolts.

7. A reinforcing rib is joined to the wide surface at the end of the longitudinal direction of the core material so as to be perpendicular to the wide surface, forming a cross-shaped cross section; 7. The buckling restraint brace according to claim 1, wherein the wooden restraint material has a slit at a position corresponding to the reinforcing rib so as not to interfere with the reinforcing rib.

8. The buckling restraint brace according to claim 7, characterized in that, in a plan view, there is a gap between the slit and the reinforcing rib.

9. 9. The buckling restraint brace according to claim 1, wherein an insert plate is interposed between the wide surface of the core material and the restraint plate.

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