JP7537412B2 - Buckling restraint brace and structure equipped with said buckling restraint brace - Google Patents

Description

The present invention relates to a buckling restraint brace consisting of a steel core member with a cross-shaped or H-shaped cross section and a pair of wooden buckling restraint members, and to a structure equipped with the buckling restraint brace.

In buildings, braces are sometimes installed as components to resist shear forces during earthquakes. Braces are installed diagonally within the plane of the frame and are primarily used to resist shear deformation of a story caused by earthquake loads.
During an earthquake, axial tensile and compressive loads are repeatedly applied, so the braces are required to have sufficient strength and energy absorption capacity against both loads.

Generally, when an axial compressive load is applied, there is a risk of buckling occurring in a member, and the occurrence of buckling reduces the member's strength and energy absorption capacity.
Since braces can also experience a decrease in strength and energy absorption capacity due to buckling, there are buckling-restrained braces that consist of a core material that resists earthquake loads and a buckling restraint material that is arranged to cover the core material to suppress buckling deformation of the core material.
8 and 9 show such a buckling restraint brace 41 disposed within the plane of a frame formed by columns 43 and beams 45.

The buckling restraint material is required to have sufficient strength to resist bending deformation due to buckling of the core material, and the buckling restraint material or its joints are required to have sufficient strength to resist local compressive forces due to buckling deformation of the core material.
Figure 10 is a cross-sectional view of a buckling restraint brace 41 consisting of a core material 47 and a buckling restraint material 49. Cross-sectional shapes of conventional core material 47 include a plate (see Figure 10(a)), circle (see Figure 10(b)), cross (see Figure 10(c)), H-shape (see Figure 10(d)), etc., and the buckling restraint material 49 covering the core material 47 is often box-shaped (see Figures 10(a), (c), and (d)) or circle (see Figure 10(b)).

The larger the gap between the buckling restraint material 49 and the core material 47, the higher the strength required of the buckling restraint material 49. Therefore, in some cases, a filler 51 such as mortar is provided in the gap between the buckling restraint material 49 and the core material 47 (see FIG. 10(a)).
In addition, in order to prevent the axial force of the core material 47 from flowing to the buckling restraint material 49, an unbond material 53 may be applied or attached (see FIG. 10(a)).

The joints between both ends of the buckling restraint brace 41 and the frame can be of two types: bolt joints 55 shown in FIG. 8, which are joined by bolts; and pin joints 57 shown in FIG.
In either case, the core material 47 is made wider near the joint, high-strength steel is used, reinforcing ribs are provided, etc. to increase the strength of the core material and prevent plasticity, so that the joint does not break first. In addition, because the buckling restraint material 49 is made of steel, localized breakage due to contact with the core material 47 is unlikely to occur.

Recently, the use of wood has been promoted due to the issue of _CO2 emissions. Since wood burns down in the event of a fire, it is sometimes used for building columns and beams after being made fireproof by fireproofing. In addition, wood is sometimes used in some parts of steel structures, such as floor slabs, and the use of wood as a buckling restraint material for braces is being considered in recent years.

For example, Patent Document 1 proposes a buckling restraint brace that consists of a steel plate-shaped core material and a pair of wooden restraint materials arranged on both sides of the wide surface of the core material, with the two being bolted together at both axial ends.
Patent Document 1 also proposes forming both ends of the plate-like structure into an H-shaped cross section and disposing a pair of wooden restraining members that sandwich both sides of the web.

Furthermore, Patent Document 2 proposes a buckling restraint brace consisting of a steel plate-shaped core material, a pair of wooden restraint plates arranged on both sides of the wide side of the core material, and a pair of wooden side plates arranged on both sides of the narrow side of the core material and joined to the restraint plates.

JP 2019-214881 A JP 2020-51186 A

The structures disclosed in Patent Documents 1 and 2 basically use a plate-shaped core material, and are therefore not suitable for structures that require high strength.
In addition, in the plate-shaped core material disclosed in Patent Documents 1 and 2, when the core material becomes plastic, it also buckles in the out-of-plane deformation direction around the strong axis (the out-of-plane direction of the flange). However, since the contact surface with the restraining material is the thickness surface of the core material and is small, there is a risk that the core material will sink into the restraining material and be damaged, thereby weakening the restraint against buckling deformation.

The present invention was made to solve these problems, and aims to provide a buckling restraint brace that can be expected to have high strength and maintain restraining force even during deformation, and a structure equipped with the buckling restraint brace.

(1) The buckling restraint brace according to the present invention comprises a steel core member having a cross section and a wooden buckling restraint member arranged to cover the periphery of the core member,
The core material has elastic parts at both ends in a longitudinal direction, which elastically deform, and a plasticized part having a cross section in which the width of the horizontal part is larger than the width of the vertical part, in a portion sandwiched between the elastic parts;
The buckling restraint material consists of a pair of members joined together and arranged to sandwich the core material in the height or width direction, and has a groove portion on the joining surface of each member corresponding to the shape of the core material, and is characterized in that when the core material is arranged in the groove portion, the height-wise gap between the horizontal part of the core material and the buckling restraint material is set smaller than the height-wise gap between the vertical part of the core material and the buckling restraint material.

(2) A buckling restraint brace having a steel core member with an H-shaped cross section and a wooden buckling restraint member arranged to cover the periphery of the core member,
The core material has elastically deformable elastic parts at both ends in the longitudinal direction, the width of the flange being relatively large or the steel material having high strength, and a plasticized part having a relatively small width of the flange in a portion sandwiched between the elastic parts,
The buckling restraint material is characterized in that it consists of a pair of members joined together and arranged to sandwich the core material in the height or width direction, and the gap between the core material and the buckling restraint material is set to satisfy the following formulas (1) and (2).
sh1<sh2 ・・・(1)
sv1>sv2 ・・・(2)
Where:
sh1: Gap dimension in the width direction between the outer surface of the wide face of the flange of the core material and the buckling restraint material
sh2: Gap dimension in the width direction between the inner surface of the wide face of the flange of the core material and the buckling restraint material
sv1: Gap dimension in the thickness direction between the side surface of the flange of the core material and the buckling restraint material
sv2: Gap dimension in the thickness direction between the surface of the web of the core material and the buckling restraint material

(3) Also, in the above (1) or (2), the pair of buckling restraint members are joined by a group of bolt parts having washers and a loosening prevention mechanism.

(4) Furthermore, in any of the above (1) to (3), a slide plate is provided on the contact surface with the core material at the longitudinal end of the buckling restraint material.

(5) Furthermore, in any of the above (1) to (4), a longitudinal shear slip prevention component is provided between the pair of buckling restraint members.

(6) The frame of the present invention has a pair of columns and a pair of beams, and is characterized in that it further comprises a buckling restraint brace described in any one of (1) to (5) above within the structural surface.

In the buckling restraint brace of the present invention, the gap in the thickness direction between the horizontal part and the buckling restraint material is set smaller than the gap in the thickness direction between the vertical part of the core material in the cross section and the buckling restraint material, so when the core material deforms, the water side part with a large area abuts against the groove wall of the buckling restraint material. This makes it possible to prevent the core material from sinking into the buckling restraint material, and high strength can be expected while the restraint force can be maintained even during deformation.

FIG. 1 is an explanatory diagram of a buckling restraint brace according to embodiment 1, and FIG. 1(a) is a cross-section taken along the line AA in FIG. 1(b) (part 1). 2A is an explanatory diagram of a buckling restraint brace according to embodiment 1, and FIG. 2A is a cross-section taken along the line AA in FIG. 2B (part 2). 1 is an explanatory diagram of the gap between the core material and the buckling restraint material of the buckling restraint brace of embodiment 1. FIG. 4A is an explanatory diagram of a method for joining a buckling restraint member consisting of a pair of members in a buckling restraint brace according to embodiment 1, and FIG. 4A is a cross section taken along the line AA in FIG. 4B. 5A is an explanatory diagram of another aspect of the buckling restraint brace according to embodiment 1, and FIG. 5(a) is a cross section taken along the line AA in FIG. 5(b). FIG. 11 is an explanatory diagram of a buckling restraint brace according to embodiment 2. 7A and 7B are explanatory diagrams of a buckling restraint brace according to an embodiment, in which FIG. 7A is a detailed diagram of a core material, FIG. 7B is a detailed diagram of a joint of a buckling restraint material, and FIG. 7C is an overall configuration diagram. This is an explanatory diagram of a typical buckling restraint brace installed within the frame plane (part 1). This is an explanatory diagram of a typical buckling restraint brace installed within the frame plane (part 2). FIG. 1 is an explanatory diagram of the core material and buckling restraint material of a typical buckling restraint brace.

[First embodiment]
The buckling restrained brace 1 according to this embodiment will be described with reference to Figures 1 to 3. Figure 1 shows a state in which the core material 3 and the buckling restrained material 5 are separated, and Figure 2 shows a state in which the core material 3 and the buckling restrained material 5 are integrated together.
1(a) shows a cross section taken along line A--A in FIG. 1(b), and FIG. 2(a) shows a cross section taken along line A--A in FIG. 2(b).

As shown in Figures 1 and 2 , the buckling restraint brace 1 of this embodiment comprises a steel core material 3 with a cross cross section and a wooden buckling restraint material 5 arranged to cover the periphery of the core material 3.
Each component will be described in detail below.

<Core material>
The core material 3 is a steel component having a cross-sectional shape, and has elastic portions 7 at both ends in the longitudinal direction that can elastically deform, and a plasticized portion 9 having a cross-sectional shape in which the width of the horizontal portion is greater than the width of the vertical portion, located between the elastic portions 7.
In order to prevent plasticization, the elastic portion 7 has a cross section having a larger thickness and width than the plasticized portion 9 at the center in the longitudinal direction.
In order to prevent the elastic portion 7 from becoming plastic, the strength of the elastic portion 7 may be increased by the above-mentioned shape, or a steel material having a higher strength than the plastic portion 9 may be used.

In this embodiment, both ends of the core material 3 are bolted to the frame with high-strength bolts, so the elastic portion 7 has a bolt hole 11 at the end of the bolt joint 13. However, in the case of a pin joint, a clevis is provided at the end of the elastic portion 7.

<Buckling restraint material>
The buckling restraint material 5 consists of a pair of wooden members joined together so as to sandwich the core material 3 from the height direction, and the joint surfaces of each member have grooves 15 corresponding to the shape of the core material 3 (see Figure 1 (a)).
The buckling restraint material 5 is intended to sandwich and join the core material 3 from both sides in the thickness direction of the core material 3, and the groove portions 15 provided in each component of the buckling restraint material 5 are deep grooves that align with the vertical portion of the cross section of the core material 3, and shallow grooves that align with the horizontal portion of the cross section of the core material 3.
The buckling restraint material 5 may sandwich the core material 3 in the width direction (the direction perpendicular to the height direction).
The wood used for the buckling restraint material 5 may be a wood material such as laminated timber, LVL, CLT, etc. In addition, taking into consideration the initial shape irregularity of the core material 3, the size of the groove portion 15 needs to be made slightly larger than the cross-sectional shape of the core material 3.

Therefore, when the core material 3 is disposed in the groove portion 15, a gap is generated between the core material 3 and the groove wall, but the gap S1 in the height direction at the horizontal part of the cross section of the core material 3 is set smaller than the gap S2 in the height direction at the vertical part of the cross section of the core material 3 (see Figure 3).

If the contact area between the core material 3 and the wooden buckling restraint material 5 is small when the core material 3 buckles, there is a risk that the core material 3 will sink into the wood, causing the wood to break, making it impossible to restrain the buckling deformation of the core material 3. Therefore, when the core material 3 undergoes out-of-plane deformation around the weak axis (in the direction of the beam), the horizontal part that provides a large contact area is made to come into contact with the buckling restraint material 5 first, preventing the wood from sinking in due to contact with the core material 3 and achieving high restraint.

As shown in Figure 3, the gap between the core material 3 and the groove wall in the width direction is set to be smaller than the gap S3 in the width direction of the horizontal part of the cross section of the core material 3, which is the vertical part of the cross section of the core material 3. This allows the vertical part, which has a larger contact area, to come into contact with the buckling restraint material 5 first when the core material 3 deforms out-of-plane around the strong axis (width direction), preventing the wood from sinking due to contact with the core material 3 and achieving high restraint.

A pair of buckling restraint materials 5 are joined to the core material 3 with a plate to prevent penetration between them. Joining methods include mechanical joining using bolts, screws, lag screw bolts, drift pins, etc., joining with adhesives, or joining using a combination of these. When joined, the buckling restraint materials 5 have sufficient strength against the extrusion force in the out-of-plane direction due to contact with the core material 3, preventing the buckling restraint materials 5 from separating from each other, resulting in excellent buckling restraint properties.

As described above, with the buckling restraint brace 1 of this embodiment, the core material 3 is cross-shaped, so it is expected to have a higher strength than a plate-shaped one. Furthermore, by using wood as the buckling restraint material 5 and having the horizontal part, which provides a larger contact area, come into contact with the buckling restraint material 5 first when the core material 3 deforms out-of-plane around the weak axis (in the direction of the beam), it is possible to prevent the wood from collapsing and breaking, and a high restraining effect can be expected.

Although there is no particular limitation on the method for joining a pair of buckling restraint members 5 together, it is preferable to join them using a washer 17 and a bolt part group 23 having an anti-loosening mechanism (nut 19, washer 21), as shown in Figure 4.
This allows the buckling restraint members 5 to be mechanically joined to each other by the bolt parts group 23, and prevents the buckling restraint members 5 from separating due to contact with the core material 3.

In this case, the wooden buckling restraint member 5 is provided with a bolt hole 27 into which the bolt 25 is inserted. It may also be provided with a counterbore 29. The size and shape of the counterbore 29 are set to match the shape of a washer for bolt connection and to be larger than the washer.
By covering the countersink 29 with wood after the bolts are fastened, the bolted joint portion 13 minutes can be hidden, resulting in a brace with excellent design.

The washer 17 is necessary to ensure the strength of the bolted joint by widening the contact area and preventing the wood from being crushed by the bolt. To prevent the nut 19 from loosening, a spring washer, an idling, or a double nut can be used. Figure 4 shows the double nut type.
The bolt connections are provided at positions outside the width of the core material 3 (see FIG. 4(a)) and in the axial direction of the core material 3. The spacing between the bolts 25 and the sizes of the bolts 25 and washers 17 are determined according to the buckling wavelength of the buckling restraint material 5 and the calculated value of the required buckling stiffening force.

The pair of wooden buckling restraint members 5 is preferably joined in a way that prevents shear slippage in the longitudinal direction. When bending deformation occurs in the buckling restraint member 5 due to contact with the core material 3, shear slippage in the longitudinal direction occurs between the pair of buckling restraint members 5. If the joining method does not prevent this shear slippage, each of the pair of buckling restraint members 5 will individually resist bending, resulting in a bending mechanism as what is known as a stacked beam.

On the other hand, in the case of a joining method capable of preventing shear slippage, a pair of buckling restraint members 5 act as a single body to resist bending, which is a so-called composite beam bending mechanism. In the case of a composite beam bending mechanism, the resistance of the core member 3 to bending buckling is increased, which is preferable since the size of the buckling restraint members 5 can be kept small.
As a joining method for preventing shear slippage, for example, a pair of buckling restraint members 5 may be joined by a drift pin or a lag screw bolt. The drift pin or the lag screw bolt may be used in place of all or part of the bolts 25, or may be used in addition to the bolts 25.

As shown in FIG. 5, it is preferable to provide a slide plate 31 on the contact surface with the core material 3 at the longitudinal end (elastic portion 7) of the wooden buckling restraint member 5.
When the joints at the longitudinal ends of the buckling restrained brace 1 deform, as in the case of the pin joint type, the wooden buckling restrained members 5 are pushed by the buckling deformation of the core material 3 at the longitudinal ends of the buckling restrained members 5, but the contact area at the corners of the longitudinal ends is small, so there is a risk that the wooden buckling restrained members 5 will sink in and break. For this reason, it is desirable to provide parts at the longitudinal ends to prevent breakage of the wooden buckling restrained members 5 due to contact with the core material 3.

Here, if a material with a high coefficient of friction is used for the penetration fracture prevention component, an axial load may act on the buckling restraint material 5 due to contact with the core material 3, reducing the buckling restraint effect. For this reason, it is preferable to use a slide plate 31 with a small coefficient of friction as the penetration fracture prevention component. The material of the slide plate is not particularly limited, and any material with a small coefficient of friction may be used.

[Embodiment 2]
The core material 3 in the first embodiment has a cross-shaped cross section, but the core material 3 in the present embodiment differs from the first embodiment in that it has an H-shaped cross section having a web 3W and a flange 3F, as shown in FIG.
Figure 6 is a diagram for explaining the characteristic parts of the buckling restraint brace 1 according to this embodiment, and corresponds to Figure 3 in embodiment 1. In Figure 6, the same parts as and corresponding parts to Figure 3 are given the same reference numerals.

Similar to embodiment 1, the buckling restraint brace 1 of this embodiment has grooves that match the shape of the core material 3 and is equipped with a pair of wooden buckling restraint members 5 that are joined together and sandwich the core material 3.
As mentioned above, if the narrow surface of the core material 3 comes into contact with the wooden buckling restraint material 5 first, there is a risk that the wood will sink and break, reducing the buckling restraint force. Therefore, in this embodiment as well, the gap between the core material 3 and the buckling restraint material 5 is specified so that the wide surface of the core material 3 comes into contact first.
Specifically, it is configured as follows:

The buckling restraint brace 1 according to this embodiment comprises a steel core member 3 having an H-shaped cross section, and a wooden buckling restraint member 5 arranged to cover the periphery of the core member 3.
The core material 3 has elastic portions 7 at both ends in the longitudinal direction, where the flange 3F has a relatively large width or where the steel strength is high, and has plasticized portions 9 in which the flange 3F has a relatively small width in the portion sandwiched between the elastic portions 7.
In addition, as shown in Figure 6, the buckling restraint material 5 consists of a pair of members that are arranged and joined so as to sandwich the core material 3 in the thickness direction, and the gap between the core material 3 and the buckling restraint material 5 is set to satisfy the following equations (1) and (2).
sh1<sh2 ・・・(1)
sv1>sv2 ・・・(2)
Where:
sh1: Gap dimension in the width direction between the outer surface of the wide face of the flange of the core material and the buckling restraint material
sh2: Gap dimension in the width direction between the inner surface of the wide face of the flange of the core material and the buckling restraint material
sv1: Gap dimension in the thickness direction between the side surface of the flange of the core material and the buckling restraint material
sv2: The gap dimension in the thickness direction between the surface of the web of the core material and the buckling restraint material. As in embodiment 1, the buckling restraint material 5 may be configured to sandwich the core material 3 in the width direction (direction perpendicular to the thickness direction).

With the above-described configuration, when the core material 3 buckles and deforms in the out-of-plane direction of the web 3W, the wide surface of the web 3W or the narrow surface of the flange 3F comes into contact with the buckling restraint material 5. However, since the gap sv2 between the surface of the web 3W and the buckling restraint material 5 is specified to be smaller than the gap sv1 between the narrow surface of the flange and the buckling restraint material 5, the wide surface of the web 3W, which has a larger contact area, comes into contact first.
In addition, if the core material 3 buckles and deforms in the out-of-plane direction of the flange 3F, the outside of the wide surface of the flange 3F or the inside of the wide surface of the flange 3F comes into contact with the buckling restraint material 5. However, since the gap sh1 between the outside of the wide surface of the flange and the buckling restraint material 5 is specified to be smaller than the gap sh2 between the inside of the wide surface of the flange and the buckling restraint material 5, the outside of the wide surface of the flange 3F, which has a larger contact area, comes into contact with the buckling restraint material 5 first.
This makes it possible to prevent the buckling restraint member 5 from being destroyed by contact with the core material 3 even if the core material 3 has an H-shaped cross section, thereby achieving high restraint.

In the above first and second embodiments, the buckling restraint brace 1 has been described, but the present invention is not limited to a single buckling restraint brace, but includes a frame having a pair of columns and a pair of beams, and further including a buckling restraint brace 1 within the structural plane. Such a frame is expected to have a higher strength than one equipped with a conventional buckling restraint brace.

The following arrangement is preferable for the buckling restraint brace 1 in the frame.
Of the gaps between the core material 3 of the buckling restraint brace 1 and the buckling restraint material 5, the gap parallel to the plane including the column-beam is defined as A, and the gap perpendicular to the plane is defined as B. The buckling restraint brace 1 is positioned within the structural plane so that A > B.
The above arrangement effectively prevents out-of-plane buckling of the structural members.

The buckling restraint effect when wood is used as the buckling restraint material was confirmed in accordance with the design guidelines for the conventional buckling restrained brace 41, and this will be described below.
According to a non-patent document (Architectural Institute of Japan, Guidelines for Design of Steel Structures with Vibration Control, November 2014), the buckling-restrained brace 41 requires both a bending buckling restraint condition for restraining bending deformation caused by buckling of the core material 47, and a local collapse condition for preventing local destruction at the bolt joint 13 and the like due to the stiffening force caused by contact between the core material 47 and the stiffener (buckling restraint material). These bending buckling restraint conditions and local collapse conditions are as follows:

[Buckling constraint conditions]
The buckling restraint material 5 maintains elasticity against the design axial force _d N _max and is designed in accordance with the following equation so that bending buckling does not occur.

[Local collapse condition]
The buckling restraint material 5 is designed so as not to collapse locally due to the stiffening force B shown in the following formula.

The structure of the buckling restrained brace 1 under consideration is shown in Figure 7. The core member 3 is a steel material with a yield strength of 235N/ ^mm2 , and is a cross-sectional member with a width of 140mm, depth of 86mm, and plate thickness of 16mm.
The buckling restraint material 5 is a pair of wooden pieces with grooves that match the shape of the core material 3, as shown in Figure 7, each 300 mm wide and 150 mm deep. The wooden pieces have a bending Young's modulus of 8000 N/ ^mm2 , a bending strength of 31.5 N/ ^mm2 , and a compressive strength of 8.1 N/ ^mm2 .
The tangent modulus _Et of the core material 3 is set to 0.05 times the Young's modulus. Table 1 shows the results of the study on the bending buckling restraint conditions, and Table 2 shows the results of the study on the local collapse conditions.

As shown in Table 1, the left side minus the right side of equation (3) in Mathematical formula 1 is greater than 0, and the bending buckling constraint condition is satisfied.
Furthermore, as shown in Table 2, both the bolt strength and the embedment strength of the washer 17 are greater than the stiffening force B, and satisfy the local collapse conditions.
From the above, it is considered that the structure shown in FIG. 7 satisfies the design conditions of existing stiffening members (buckling restraint braces) and has sufficient performance as a buckling restraint member 5.

Next, the influence of the core material 3 embedding in the wooden buckling restraint material 5 was examined, and will be described below.
If the core material 3 sinks 2 mm into the wood, the gap s between the other core material 3 and the buckling restraint material 5 increases by 2 mm. Therefore, the results of examining the bending buckling restraint conditions and local collapse conditions described above with s = 6 mm are shown in Tables 3 and 4.

Since the stiffening force B is proportional to the gap s between the core material 3 and the buckling restraint material 5, it can be seen that as the gap s increases, the stiffening force B becomes extremely large. In addition, the bolt strength and the compressive strength of the washer 17 must be increased, so it can be seen that preventing compressive stress is important in achieving reasonable buckling restraint specifications.
From this point of view, it can be seen that it is effective to adjust the gap between the core material 3 and the buckling restraint material 5 so that the narrower plate thickness surface of the core material 3 does not come into contact first, as in the present invention, and to minimize the embedding of the core material 3 into the buckling restraint material 5 at the contact surface.

REFERENCE SIGNS LIST 1 Buckling restrained brace 3 Core material 3W Web 3F Flange 5 Buckling restrained material 7 Elastic portion 9 Plasticized portion 11 Bolt hole 13 Bolt joint portion 15 Groove portion 17 Washer 19 Nut 21 Washer 23 Bolt component group 25 Bolt 27 Bolt hole 29 Counterbore 31 Slide plate 41 Buckling restrained brace (conventional)
43 Column 45 Beam 47 Core material 49 Buckling restraint material 51 Filler material 53 Unbonded material 55 Bolted joint 57 Pin joint

Claims (6)

A buckling restraint brace comprising a steel core member having a cross section with a horizontal portion and a vertical portion , and a wooden buckling restraint member arranged to cover the periphery of the core member,
The core material has elastic parts at both ends in a longitudinal direction, which elastically deform, and a plasticized part having a cross section in which the width of the horizontal part is larger than the width of the vertical part, in a portion sandwiched between the elastic parts;
The buckling restraint brace is characterized in that the buckling restraint material consists of a pair of members joined and arranged to sandwich the core material in the width direction of the horizontal portion or the height direction of the vertical portion , whereby portions of the joint surfaces of each member are in contact with each other and have grooves on the joint surfaces corresponding to the shape of the core material, and where when the core material is arranged in the groove, the gap between the buckling restraint material and the horizontal portion of the core material in the height direction is set smaller than the gap between the buckling restraint material and the vertical portion of the core material in the height direction. A buckling restraint brace comprising a steel core member having an H-shaped cross section with a web and a flange , and a wooden buckling restraint member arranged to cover the periphery of the core member,
The core material has elastically deformable elastic parts at both ends in the longitudinal direction, the width of the flange being relatively large or the steel material having high strength, and a plasticized part having a relatively small width of the flange in a portion sandwiched between the elastic parts,
The buckling restraint brace is characterized in that the buckling restraint material is composed of a pair of members that are arranged and joined so as to sandwich the core material in the thickness direction, which is the width direction of the flange , and portions of the joint surfaces of each member are in contact with each other and have grooves corresponding to the shape of the core material on the joint surfaces, and the gap between the core material and the buckling restraint material is set to satisfy the following formulas (1) and (2).
sh1<sh2 ・・・(1)
sv1>sv2 ・・・(2)
Where:
sh1: Gap dimension in the width direction between the outer surface of the wide face of the flange of the core material and the buckling restraint material
sh2: Gap dimension in the width direction between the inner surface of the wide face of the flange of the core material and the buckling restraint material
sv1: Gap dimension in the thickness direction between the side surface of the flange of the core material and the buckling restraint material
sv2: Gap dimension in the thickness direction between the surface of the web of the core material and the buckling restraint material The buckling restraint brace according to claim 1 or 2, characterized in that the pair of buckling restraint members are joined by a group of bolt components having washers and a loosening prevention mechanism. The buckling restraint brace according to any one of claims 1 to 3, characterized in that a slide plate is provided on the contact surface with the core material at the longitudinal end of the buckling restraint material. A buckling restraint brace as described in any one of claims 1 to 4, characterized in that a longitudinal shear slip prevention component is provided between the pair of buckling restraint members. A frame having a pair of columns and a pair of beams, further comprising a buckling restraint brace according to any one of claims 1 to 5 within the structural plane.