JP2001214541A - Buckling restraint brace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-cost buckling restraint brace being slender as a whole and lightweight, having a stable restoration force characteristic with a small difference between compressed and tensile bearing strength, and being easy to fabricate. SOLUTION: A flanged steel plate 3 is provided at the end of a core 2 comprising a steel plate, with flanged steel plate perpendicular to the core 2. A buckling stiffener 4 for restraining deformation of the core in a direction perpendicular to its axis is assembled by fillet welding or the like of the steel plate. A shock absorber 5 is affixed to the inner surface of a buckling restraining member 4. Connections to the principal skeletons of a structure are made via the flanged steel plate 3 provided at the end of the core 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is incorporated between layers of a main frame of a structure, and when a large interlayer deformation occurs, a steel material serving as a core material is plastically deformed to absorb energy and to shake the structure. Buckling restrained braces that reduce

[0002]

2. Description of the Related Art A conventional buckling restrained brace is disclosed in Japanese Utility Model Publication No. 4-191121. This is a steel plate serving as a core material, which is buckled and restrained by steel pipe concrete, and an anti-adhesion coating made of a mold release agent, oil paint, or asphalt is applied and formed between the core material and the concrete. I have.

[0003] Further, there is also described a structure in which a reinforcing rib plate is provided at an end portion of a core material, and a cross-section is formed by a steel plate of the core material and the rib plate, so that an axial deformation allowance of the core material is secured. For this purpose, a deformation absorbing elastic material made of synthetic resin sponge or rubber is provided on the end face of the rib plate.

Further, as an example of using a steel material as the buckling restraint member, there is one described in, for example, JP-A-9-221830. In this method, a steel plate serving as a core material is inserted into a stiffening pipe made of a round steel pipe or a square steel pipe, and is buckled and restrained by a buckling stopper provided inside the stiffening pipe. The brace and the main structural frame are joined via a cross-shaped steel plate welded to both ends in the axial direction of the core material.

Japanese Unexamined Patent Publication No. Hei 11-17283 discloses a further development of the technique disclosed in Japanese Unexamined Patent Publication No. Hei 9-221830, in which a steel plate serving as a core material and a rectangular steel pipe serving as a buckling restraint material come into contact with each other. There is disclosed a structure in which two liners are sandwiched in a portion, and a lubricant is interposed between the two liners.

[0006] In addition, Japanese Patent Application Laid-Open No. 10-3 by the present applicant.
Japanese Patent Application Laid-Open No. 06498 discloses a light-weight, thin buckling-restrained brace that can provide a sufficient stiffening effect without increasing the cross-section of the brace, is easy to manufacture, fits easily, and is a core of a steel plate as a core material. It is disclosed that thickened portions are provided at both ends in the direction, the thickened portions being thicker than the central portion.

[0007]

SUMMARY OF THE INVENTION The above-mentioned Japanese Patent Application Laid-Open No. Hei 9-2
In the case of the buckling restrained brace described in Japanese Patent No. 21830, the steel plate serving as the core material and the steel pipe serving as the buckling restraint material are in contact with only a part of the core material cross-sectional end or the like, and the cross section of the steel plate serving as the core material Most are not buckled.

Further, in the case where the buckling restraining member is a rectangular steel pipe and the corner of the rectangular steel pipe is in contact with the core material, the buckling restraining force is concentrated on the corner of the steel pipe, and the portion is locally localized. There is a risk that the buckling restraint effect may not be sufficiently exerted due to the deformation.

[0009] Further, the direct contact between the steel plate as the core material and the corners of the rectangular steel pipe as the buckling restraint member locally increases the frictional force, and when compressive force acts on the brace, the proof stress is reduced accordingly. As a result, there is a danger that the difference between the proof stress on the tensile load side and the proof stress on the compressive load side in the restoring force characteristics is significantly different.

In addition, it is pointed out that it is difficult to manage the gap between the inner diameter of the steel pipe and the steel plate as the core material in the production of the brace. To solve such a problem, Japanese Patent Laid-Open No.
According to the invention described in JP-A-1-177883, two liners are sandwiched between a steel plate serving as a core material and a corner portion where a rectangular steel pipe serving as a buckling restraint member comes into contact, and a lubricant is interposed between the two liners. Is interposed.

This is considered to suppress the increase in frictional force and solve the problem that the restoring force characteristics are significantly different between the tensile load side and the compressive load side to some extent. However, the addition of the liner plate and the lubricating material is considered. This leads to an increase in man-hours for manufacturing the buckling restrained braces.

Further, the problem that most of the cross section of the steel plate as the core material is not buckled and the buckling restraining force is concentrated on the corners and the corners of the steel pipe are locally deformed remains as before. I have.

When a buckling restrained brace is used as a vibration control device, it is necessary that the end of the brace material stays in an elastic range until the core material of the brace is plasticized to some extent and the building exhibits a vibration control effect.

At this time, the shape of the end portion of the brace material has a shape in which a vertical rib is joined to the material end portion in the axial direction of the core material as disclosed in Japanese Utility Model Publication No. 4-19121 and Japanese Patent Application Laid-Open No. 9-221830. When checking the allowable stress in the cross section composed of the core material and the vertical ribs, the allowable stress is not affected even if the vertical ribs are made of ordinary steel or high-tensile steel with higher material strength than the core material. In some cases, it is necessary to use the value of the extremely low yield point steel having low strength used for the core material.

Although the degree of plasticization of the brace for exhibiting the vibration damping effect is not generally determined, for example, a very low yield point steel having a brace axial strain piece amplitude of 1% and a core material having a low yield point is used. In this case, it is estimated that the rate of increase of the yielding axial force is at least twice.

In such a case, the cross-sectional area at the end of the brace material is required to be at least twice the cross-sectional area of the core material.
Further, in the case of bolt joining, the end of the brace material has a considerably larger shape than the center section of the core material in consideration of the cross-sectional area of the bolt hole loss.

This is a major factor that increases the plate loss when removing the brace core material and increases the manufacturing cost.
In addition, the large shape of the end of the brace material also increases the joining portion on the main structure side to be joined to the brace, which also increases the cost of the design on the main structure side.

The present invention has been made to solve the above-mentioned problems, and is thin and lightweight as a whole, has a small difference in proof stress between compression and tension, and exhibits stable restoring force characteristics. It is intended to provide an easy low cost buckling restrained brace.

[0019]

According to a first aspect of the present invention, there is provided a buckling restrained brace comprising a core made of a steel plate and a steel buckling restraint provided around a cross section of the core. A flange steel plate that is substantially orthogonal to the width direction of the core is provided at both ends in the width direction of the end of the core protruding from the end of the buckling restraint member. .

In this case, if the buckling restraint member is arranged so as to be substantially in close contact with the periphery of the core material, the buckling restraint effect can be efficiently obtained, and the weight of the steel material required for the buckle restraint member can be reduced. You.

The flange steel plate provided at the material end of the core material has an effect of stiffening the material end by forming, for example, an H-shaped cross section together with the core material. In this case, the design can be performed with the material strength of the flange steel plate during the stress check. The connection with the main skeleton can be performed at at least one of the position of the flange steel plate and the core material.

According to a second aspect of the present invention, in the buckling restrained brace according to the first aspect, a thickened portion in which the thickness of the core material is increased is formed at least in a part of the end portion of the core material in the width direction. An enlarged hole or an end face is opened at the end of the buckling restraint member to allow movement of the thickened portion in accordance with the axial deformation of the core material in accordance with the thickness of the thickened portion. The case where the slit is formed is limited.

Since the core material is allowed to deform in the axial direction,
Depending on the design of the buckling-restrained brace, there is a core-only portion between the end of the buckling-restraint material and the portion where the flanged steel plate is provided at the end of the brace material. While this may be a point, claim 2 addresses this problem by reinforcing this portion with a thickened portion.

Such a thickened portion can be easily formed by, for example, overlapping and joining a reinforcing steel plate to the end of the core material. On the other hand, by forming the enlarged hole at the end of the buckling restraint member, it is possible to secure a deformation allowance associated with the axial deformation of the core material in the enlarged hole.

When the reinforcing steel plate is joined in the direction orthogonal to the axial direction of the core, an open slit may be formed at the end of the buckling restraint member. In this case, since the reinforcing steel sheet enters the slit, the deformation allowance accompanying the axial deformation of the core material can be secured, and the portion of the core material alone can be eliminated.

According to a third aspect of the present invention, in the buckling restrained brace according to the first aspect, at least a portion of the cross section of the end portion of the buckling restraining member that restrains deformation of the core material in a direction perpendicular to a width direction thereof. The case where the portion is extended in the direction of the material axis and extends to the vicinity of the installation position of the flange steel plate of the core material is limited.

In this case, as in the invention according to claim 2,
Without forming a thickened portion in the core material, a portion of only the core material can be eliminated in the extension of the buckling restraint member, and a weak point for buckling can be eliminated.

In the case where the section of the buckling restrained brace in which the cross section is only the core material is short and there is no possibility that the core material will locally buckle in that section, consideration must be given to the inventions of claims 2 and 3. Disappears.

According to a fourth aspect, in the buckling restrained brace according to the first, second or third aspect, a cushioning material is interposed between the core material and the buckling restraining material. By interposing the cushioning material, the frictional force between the core material and the buckling restraint material can be reduced, so that a stable restoring force characteristic against tension and compression can be exhibited.

The material of the cushioning material is not particularly limited as long as it can reduce the frictional force between the core material and the buckling restraint material. It is conceivable to insert the cushioning material between the core material and the buckling restraint material. In this case, it is desirable to insert the cushioning material over the entire width and substantially the entire length of the plastic deformation section of the core material.

As the kind of the cushioning material, since tear strength and abrasion resistance are required, natural rubber, isoprene rubber,
Chloroprene rubber, nitrile butadiene rubber, urethane rubber and the like are suitable. Hardness is JIS hardness 70-10
About 0 is necessary. When a cushioning material is attached, it is preferable to attach the cushioning material to the buckling restraint material side.

According to a fifth aspect, in the buckling restrained brace according to the first, second, third or fourth aspect, the central portion of the core member in the axial direction and the central portion of the buckling restraining member in the axial direction are joined or engaged. It is when stopped.

The reason why the central portion is joined or locked is to eliminate the displacement between the core member and the buckling restraint member so that the deformation allowance at both ends is substantially the same. More specifically, the adhesive is applied between the central portion in the axial direction of the core material and the inner surface of the central portion in the axial direction of the buckling restraint member (if the cushioning material is interposed, between the cushioning material). Means for applying and joining, or providing a convex portion in the axial center of the core material, providing a concave portion in the axial central portion of the buckling restraint member for locking the convex portion, and locking these. There is.

A sixth aspect of the present invention is the buckling restrained brace according to the first, second, third, fourth or fifth aspect, wherein the material strength of the flange steel plate is equal to or greater than the material strength of the core material. As described in relation to claim 1, by connecting with the main skeleton through the flange steel plate provided at the end of the core material, it is possible to design with the material strength of the flange steel plate at the time of stress check. However, for example, when the core material is an extremely low yield point steel, by using ordinary steel or high-strength steel for the flange steel plate, the joint with the main frame is also made compact.

[0035]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG.
1 shows an embodiment of a buckling-restrained brace 1 corresponding to FIG. 1, in which a flange steel plate 3 is provided at an axial end of a core material 2 made of a steel plate so as to be orthogonal to the core material 2.

The buckling restraint member 4 in this embodiment is assembled by fillet welding using a flat steel plate around the cross section of the core material 2 so as to restrain deformation of the core material 2 in the direction perpendicular to the material axis. I have. Further, a sheet-like cushioning material 5 is attached to a parallel portion on the inner surface of the buckling restraint material 4.

In this example, the width of the steel plate serving as the core 2 is constant in the direction of the material axis, and a reinforcing plate as shown in FIGS. Since it is not provided, it is compact and has no waste as compared with the one in which the plate width changes or the one in which a reinforcing plate is attached, and the cost can be reduced.

Further, the buckling restraint member 4 and the core member 2 are
The core material 2 is prevented from slipping by the adhesive 7 attached to the
And the buckling restraint member 4 is eliminated so that the deformation allowance at both ends is substantially the same.

FIG. 2 shows another embodiment of the buckling restrained brace 1 according to the first, fourth and fifth aspects of the present invention.
Details of the end of the core 2 and the end of the buckling restraint 4;
The cross-sectional shape of the buckling restraint member 4 and the arrangement of the sheet-like cushioning material 5 are the same as those in FIG. In this example, the buckling restraint 4 and the core 2 are prevented from slipping, and the core 2
Are provided at the center of the buckling restraining member 4, and a pair of steel pieces 9a are attached to the upper and lower portions of the
Are formed, and the convex portion 8 on the core member 2 side and the concave portion 9 on the buckling restraint member 4 side are formed.
The buckling restraint member 4 and the core member 2 are prevented from being displaced by engagement with each other, and the deformation allowance at both ends is substantially the same.

The projections 8 on the side of the core 2 are preferably rounded to avoid concentration of stress. Further, from the viewpoint of fatigue resistance, a flat steel plate used for the core material 2 is cut out rather than welding a slab or the like for the convex portion 8, and the central portion in the axial direction becomes wider (convex portion) than a normal section. It is good to manufacture it.

FIG. 3 shows an embodiment of the buckling restrained brace 1 corresponding to claim 2 of the present application. Flange steel plates 3 are provided above and below the axial end of a steel plate serving as a core material 2. The points provided orthogonal to the core material 2 and the arrangement of the sheet-like cushioning material 5 are the same as those in the embodiment of FIGS. 1 and 2, but in the example of FIG. The reinforcing steel plate 10 is provided to increase the thickness.

Along with this, an enlarged hole is formed at the end of the buckling restraint member 4 using a steel plate 11, and the reinforcing steel plate 10 is used to increase the thickness of the buckling restraint member 4 with the axial deformation. The deformation allowance is ensured by allowing the thick part to move into the enlarged hole.

In this example, as shown in FIG. 3E, the width of the reinforcing steel plate 10 used for the thickened portion at the end of the core material 2 is made smaller than the width of the core material 2 to enlarge it. At the four corners of the hole, at positions not interfering with the reinforcing steel plate 10, steel pieces 12 for restraining deformation of the core material 2 in a direction perpendicular to the axis are provided. That is, also in the deformation allowance portion, the deformation in the direction perpendicular to the axis of the core material 2 is restrained by the steel pieces 12 at the four corners, and local buckling at the deformation allowance portion is suppressed.

It is desirable that the length of the steel slab 12 be at least twice as long as the deformation allowance of the core material 2, and when the reinforcing steel plate 10 at the end of the core material 2 is welded, The weld is designed so that it does not come into contact with the billet 12 attached to the four corners,
It is desirable that the billet 12 be in direct contact with the core material 2.

FIG. 4 shows another embodiment of the buckling restrained brace according to claim 2 of the present application, in which a flange steel plate 3 is provided above and below the axial end of the steel plate serving as the core material 2. Lumber 2
3 and the arrangement of the sheet-like cushioning material 5 are the same as those in the embodiment of FIGS. 1, 2 and 3, but in the example of FIG. Are joined in a direction perpendicular to the width direction of the core material.

Along with this, a slit 25 is formed at the end of the buckling restraint member 4 and opened to the end face side, and the reinforcing steel plate 10 enters the slit 25, whereby the core member 2 is deformed in the axial direction. As a result, the thickened portion thickened by the reinforcing steel plate 10 can be moved into the slit 25 to secure a deformation allowance, and at least a part of the thickened portion always enters the slit 25, so that the core The part of only the material has been eliminated.

FIG. 5 shows an embodiment of the buckling restraint brace 1 according to the third aspect of the present invention, in which the material end of the core member 2, the cross-sectional shape of the buckling restraint member 4, and the sheet-like shape are shown. The arrangement of the cushioning material 5 is the same as that of FIG. 1, but a part of the buckling restraint material 4, in this example, buckling restraint so as to restrain the deformation in the direction perpendicular to the width of the An extension portion 13 is provided which extends a portion constituting the front and rear surfaces of the material 4 to the position of the flange steel plate 3 at the material end of the core material 2.

In this case, it is not necessary to increase the thickness of the end portion of the core material 2 as in the case of the embodiment shown in FIGS.
The position where the cross section is only the core material 2 is eliminated, and the weak point for buckling can be eliminated.

FIG. 6 shows another embodiment of the buckling restraint brace 1 according to claim 3 of the present application. In addition to the shape shown in FIG. Vertical rib 1
4 are provided to reinforce the cross section.

FIG. 7 shows still another embodiment of the buckling restraint brace 1 according to the third aspect of the present invention. A vertical rib 14 shown in FIG. The buckling restraint 4 not only reinforces the ends of the buckling restraint, but also has the effect of overall buckling restraint and local stiffening of the buckling restraint 4 that restrains deformation in the direction perpendicular to the width of the core plate.

FIG. 8 shows still another embodiment of the buckling restrained brace 1 corresponding to claims 2 and 3 of the present application. In addition to the shape shown in FIG. A reinforcing steel plate 15 is provided on the buckling restraint member 4 to reinforce the cross section.

FIG. 9 shows still another embodiment of the buckling restrained brace 1 corresponding to claim 1 of the present application. The stress concentration at the joint between the material end of the core material 2 and the flange steel plate 3 is reduced. The width of the end portion of the core material 2 is increased to reduce the width.

FIG. 10 shows a buckling restrained brace 1 of the present invention.
FIG. 2 shows an embodiment in a case of joining a main frame of a structure with a main frame of the structure via a flange steel plate 3. In the example of FIG. 10A, the buckling restrained brace 1 and the main frame
And the high-strength bolt 1 through the splice plate 17.
6 shows a case where the bolts are joined.

FIG. 10B shows an example in which the buckling restrained brace 1 and the main skeleton are joined together by welding 18 via the flange steel plate 3. The example of FIG. 10C is a case where the buckling restrained brace 1 and the main skeleton are joined by welding 18 and 19 via the flange steel plate 3 and the core 2.

FIG. 11 shows a buckling restrained brace 1 of the present invention.
In this embodiment, the flange and the main frame of the structure are joined together with both the flange steel plate 3 and the core material 2, and both the flange steel plate 3 and the core material 2 are each subjected to high strength via a splice plate 17. Bolts are joined by bolts 16.

FIG. 12 shows a buckling restraint 4 used in the present invention.
1 shows an example of an assembling structure. FIG.
FIG. 12 (b) shows a case where two steel plates 20 are welded and assembled, and FIG.
2 (c) shows a case where the channel steel 21 and the steel plate 20 are joined together by bolts 23, and FIG. 12 (d) shows a case where two angle irons 21 are assembled by welding 22.

[0057]

According to the present invention, the buckling restraining member can be arranged so as to be substantially in close contact with the cross section of the core member, so that the buckling restraining effect can be efficiently obtained and the weight of the steel material required for the buckling restraining member is reduced. Is done.

The flange steel plate provided at the end of the core has a stiffening effect on the end of the core, and furthermore, by joining the main frame through this flange steel plate, a stress check is performed.
Design is possible with the material strength of the flange steel plate.

According to the second aspect of the present invention, the portion of the core material that may cause local buckling is reinforced by the thickened portion,
Prevent local buckling. According to the third aspect of the invention, it is possible to prevent local buckling at the extended portion of the buckling restraint member without forming a thickened portion in the core material.

According to the fourth aspect of the invention, the frictional force between the core material and the buckling restraint material can be reduced by interposing the cushioning material, whereby the stable recovery from tension and compression can be achieved. It can exert force characteristics.

In the invention according to claim 5, the central portion in the axial direction of the core member and the central portion in the axial direction of the buckling restraint member are joined or locked, so that the displacement between the two is eliminated and both ends are eliminated. The deformation allowance can be made almost the same size.

In the invention according to claim 6, since the material strength of the flange steel plate provided at the end of the core material is equal to or higher than the material strength of the core material, the joint with the main frame can be made compact.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a buckling restrained brace corresponding to claims 1, 4 and 5 of the present application, wherein (a) is a front view,
(b) is a cross-sectional view taken along the line AA, (c) is a front view of the core material with the flanged steel plate attached, (d) is a vertical cross-sectional view of the buckling restraint member in the axial direction, and (e) is the axial FIG. 4 is a vertical sectional view in a perpendicular direction.

FIGS. 2A and 2B show another embodiment of the buckling restrained brace corresponding to claims 1, 4 and 5 of the present application, wherein FIG. 2A is a front view, FIG. c) is a front view of the core material to which the flange steel plate is attached, and (d) is a vertical cross-sectional view of the buckling restraint member in the axial direction.

FIG. 3 shows an embodiment of a buckling restrained brace corresponding to claim 2 of the present application, wherein (a) is a front view, (b) is a CC cross-sectional view, and (c) is a flanged steel plate. Front view of the core material with attached, (d) is a vertical sectional view in the axial direction of the buckling restraint material,
(e) is an enlarged cross-sectional view taken along line DD of (a).

FIG. 4 shows another embodiment of the buckling restrained brace corresponding to claim 2 of the present application, wherein (a) is a front view, (b) is a front view of a core material to which a flange steel plate is attached, c) is a vertical sectional view in the axial direction of the buckling restraint member, (d) is an II sectional view of (a), (d) is an enlarged JJ sectional view of (a), and (f) is ( a) K-
(G) is an LL cross-sectional view of (a).

FIGS. 5A and 5B show an embodiment of a buckling restrained brace corresponding to claim 3 of the present application, wherein FIG. 5A is a front view and FIG.

FIGS. 6A and 6B show another embodiment of the buckling restrained brace corresponding to claim 3 of the present application, wherein FIG. 6A is a front view, and FIG.

FIG. 7 shows still another embodiment of the buckling restrained brace corresponding to claim 3 of the present application, wherein (a) is a front view,
(b) is a sectional view taken along the line GG, and (c) and (d) are enlarged sectional views perpendicular to the direction of the material axis for explaining the stiffening effect of the vertical ribs.

FIGS. 8A and 8B show still another embodiment of the buckling restrained brace corresponding to claims 2 and 3 of the present application, wherein FIG. 8A is a front view and FIG.

FIG. 9 shows still another embodiment of the buckling restrained brace corresponding to claim 1 of the present application, wherein (a) is a front view,
(b) is a front view of only the core material to which the flange steel plate is attached.

FIG. 10 shows an embodiment in which a buckling restrained brace of the present invention is joined to a main frame of a structure via a flanged steel plate. FIG. 10 (a) shows a case in which bolt connection is performed via a flanged steel plate. FIG. 4B is a front view, FIG. 4B is a front view in the case of welding connection via a flanged steel plate, and FIG. 4C is a front view in the case of welding connection via a flanged steel plate and a core material.

FIG. 11 is a front view showing an embodiment in which a buckling restrained brace and a main frame of a structure according to the present invention are bolted at both positions of a flange steel plate and a core material.

12A and 12B show an example of an assembling structure of a buckling restraint member used in the present invention. FIG. 12A is a cross-sectional view perpendicular to the axial direction of the member when four steel plates are welded and assembled. ) Is a cross-sectional view perpendicular to the axial direction when the channel steel and the steel plate are assembled by welding, and (c) is a cross-sectional view perpendicular to the axial direction when the channel steel and the steel plate are assembled by bolting (D) is a cross-sectional view perpendicular to the material axis direction when two angle irons are welded and assembled.

[Explanation of symbols]

1: buckling restrained brace, 2: core material, 3: flange steel plate,
4 ... buckling restraint material, 5 ... cushioning material, 6 ... bolt hole, 7 ... adhesive, 8 ... convex part (core material side), 9 ... concave part (buckling restraint material side),
9a: steel slab, 10: reinforced steel plate, 11: steel plate, 12: steel slab, 13: extension, 14: vertical rib, 15: reinforced steel plate, 1
6 ... high strength bolt, 17 ... splice plate, 18 ... welding with flange steel plate, 19 ... welding with core material, 20 ... steel plate, 21 ... channel steel, 22 ... welding, 23 ... bolt, 24 ...
Angle iron, 25 ... Slit

Claims (6)

[Claims] 1. A buckling restrained brace comprising a core made of a steel plate and a steel buckling restraint provided around the cross section of the core, wherein the core protrudes from an end of the buckling restraint. A buckling-restrained brace, wherein flange steel plates that are substantially perpendicular to the width direction of the core material are provided at both ends in the width direction of the material ends. 2. An end portion of the core material is formed with a thickened portion in which at least a part of the thickness of the core material in the width direction is increased. The buckling restrained brace according to claim 1, wherein an enlarged hole or a slit is formed corresponding to the thickness of the thickened portion to allow movement of the thickened portion along with deformation of the core material in an axial direction. 3. A cross section of a material end portion of the buckling restraint material, wherein at least a part of a portion for restraining deformation of the core material in a direction perpendicular to a width direction is extended in a material axis direction, and 2. The structure according to claim 1, wherein the flange plate extends to a position near the installation position.
The buckling restrained brace described. 4. The buckling restrained brace according to claim 1, wherein a cushioning material is interposed between the core material and the buckling restraining material. 5. The buckling restrained brace according to claim 1, wherein a central portion in the axial direction of the core member and a central portion in the axial direction of the buckling restraining member are joined or locked. 6. The buckling restrained brace according to claim 1, wherein the material strength of the flange steel plate is equal to or higher than the material strength of the core material.