JP5826791B2 - Buckling restraint brace - Google Patents

Description

  The present invention relates to a buckling-restrained brace using a square pipe, which is employed in a low-rise steel-based office building, an apartment house, a detached industrial house, etc., as a vibration control building.

  A buckling restrained brace is used for a wall or the like as a member that effectively prevents deformation of a building against a horizontal force acting in an earthquake or the like. The buckling-restraining brace has a plate-shaped core material and a pair of constraining materials arranged to face each other along both surfaces of the core material, and the constraining material is generally a steel material such as a groove shape and the like. It is composed of mortar, concrete, etc. However, those filled with mortar, concrete, and the like are heavy and have poor workability, and a combination of steel materials for weight reduction has been proposed (for example, Patent Documents 1 to 3).

Japanese Patent No. 4533359 Japanese Patent No. 4448528 JP 2011-169042 A

In the case of a vibration-damping building, a buckling-restrained brace having stable hysteresis performance without buckling is desired until a large interlayer deformation, for example, a large deformation exceeding 1/30. Industrialized houses are required to withstand even larger deformations of up to 1/15. In conventional buckling restrained braces, it is often difficult to withstand such large deformation.
A buckling-restraining brace that can withstand large deformations is not only deformed without buckling, but also has a structure that does not damage the joints with the housing due to interference of components or unexpected strength when large deformations occur. Is necessary.

An object of the present invention is to provide a buckling restrained brace that can secure the strength of a joint portion with respect to a frame and that does not damage the joint portion due to interference when large deformation occurs in a building.
Another object of the present invention is to provide a buckling-restrained brace that can withstand a large deformation without buckling and obtain a stable hysteresis performance.

The buckling restraint brace of the present invention has, as its basic configuration, a plate-shaped core material and a pair of restraint materials arranged opposite to each other along both surfaces of the core material, the core material at both ends, In the buckling restrained brace provided with a joint portion to be joined to the housing, the joint portion of the core material is shaped to have a portion protruding in the width direction from the other portion of the core material, than the restraint material. Reinforcing ribs were provided at both ends in the width direction of the wide joint portion .

  According to this configuration, since reinforcing ribs are provided at both ends in the width direction of the joint portion of the core material, the strength of the joint portion is ensured, and a load that causes large deformation acts on the joint portion. Damage is prevented. In addition, the joint portion of the core material is wider than the restraint material, and the reinforcing rib is provided in the projecting portion. Due to the gap, even if a large deformation occurs in the core material, the deformation rib does not contact the restraining material due to the deformation, and the joint portion is prevented from being damaged by the interference due to the contact.

  In addition, you may provide a reinforcement plate so that the said pair of restraint material may be pinched | interposed between the reinforcement ribs of the both ends of the width direction in the said junction part. This prevents the end of the restraining material from opening in the out-of-plane direction and damaging the end of the buckling restraint brace.

In this invention, the constraining material may be formed to a length that sandwiches a length range of a part of the widened joint portion of the core material. That is, it is preferable that the constraining material has a length that sandwiches the core material up to the maximum length range in a range that does not affect the joining by the joining portion.
Thereby, the deformation | transformation to the weak axis direction of a core material suppresses the pinched restraint material, and the effect | action of buckling prevention is acquired highly. The “weak axis direction of the core material” refers to the thickness direction of the flat core material, and the width direction of the core material is referred to as the “strong axis direction of the core material”.

  In this invention, it is preferable that the shape of the edge on the center side in the longitudinal direction of the core material in the protruding portion of the joint portion of the core material is an arc shape that gradually spreads from the other part. By making the shape of the edge of the protruding portion into an arc shape, the breakage can be eased.

In this invention, a width direction stiffener for restraining deformation in the width direction of the core material is provided across the pair of restraint materials, and the width direction stiffener is provided in the vicinity of the joint portion in the core material. The part is defined as a non-stiffening section without being restricted in the width direction .
Thus, by providing a width direction stiffener to the restraint material, and providing a non-stiffening section in the strong axis direction that is not stiffened by the width direction in the vicinity of the joint portion in the core material, that is, a plasticized portion of the core material By providing a strong axial non-stiffening section at the end of the armature, a bending hinge is formed in the buckling restraint brace during large deformations, which can cause damage to the restraint due to bending or axial force entering the restraint. Is prevented.
In the first buckling-restrained brace of the present invention, the width direction stiffener is provided with an end slit into which the joint portion of the core material is fitted up to the non-stiffening section .

  In particular, as described above, when the constraining material has a length that sandwiches a part of the length range of the joint portion of the core material and the portion in the vicinity of the joint portion of the core material is the non-stiffening section, At the time of deformation, the deformation in the weak axis direction is restrained by the constraining material sandwiching the core material, and in the strong axis direction, it acts as a bending hinge in the non-stiffening section, and by causing interlayer deformation near the joint, It becomes possible to satisfy the condition of withstanding a large deformation, for example, a deformation of 1/15 or more.

  When the non-stiffening section is provided as described above, reinforcing plates are provided at both side positions sandwiching the pair of restraining materials across the reinforcing ribs at both ends in the width direction, and the longitudinal direction of the width direction stiffener This end may be an intermediate position in the longitudinal direction width of the core of the reinforcing plate, and an end slit into which the joint portion of the core is fitted in the width direction stiffener may be provided up to the non-stiffening section.

  In this way, the end in the longitudinal direction of the width direction stiffener is positioned up to the middle of the reinforcing plate, and the width direction stiffener is provided with an end slit so that the core width direction is not restrained in the non-stiffening section. Like that. Thereby, local buckling of the core material in the weak axis direction can be prevented while dealing with the interlayer deformation 1/15.

When the reinforcing plate is provided as described above, the width and position in the longitudinal direction of the reinforcing plate may be the width and position in which the entire unstiffened section is accommodated.
By providing the reinforcing plate so as to cover the entire unstiffened section in this way, the effect of reinforcement is enhanced and the appearance is beautiful.

  In this invention, each said restraint material may be comprised with the steel materials, for example, may be one square pipe. In the case of a square pipe, a high stiffening effect can be obtained depending on the cross-sectional shape and the material of steel, and the weight can be reduced in proportion to the required stiffening effect compared to a restraining material filled with mortar or the like. This weight reduction leads to an improvement in workability on site.

  The buckling restraint brace of the present invention has a plate-like core material and a pair of restraint materials arranged opposite to each other along both surfaces of the core material, and the core material is joined to the building frame at both ends. In a buckling restrained brace provided with a joint, the joint of the core is made wider than the restraint in a shape having a portion protruding in the width direction from the other part of the core, and the core Since the reinforcing ribs are provided at both ends in the width direction of the joint portion of the material, the strength of the joint portion with respect to the frame can be ensured and the joint portion is not damaged by interference when large deformation occurs in the building.

Further, the constraining material is formed to have a length that sandwiches a part of the length range of the widened joint portion of the core material, and the core material is deformed in the width direction across the pair of constraining materials. widthwise stiffener to constrain, there are provided as the width direction stiffeners, and Muho rigid section a portion in the vicinity of the joint portions in the core material without constraint without stiffening in the width direction Therefore, a stable history performance is obtained withstand without buckling against large deformation. In addition, by providing end slits in the width direction stiffener, the core width direction was not restricted in the non-stiffening section, so that local buckling in the weak axis direction of the core material was achieved while meeting the requirements for interlayer deformation. Can be prevented.

(A) is a top view of the buckling restraint brace which concerns on the proposal example used as the foundation of this invention, (B) is the side view, (C) is an expanded cross-sectional view. (A) is the fracture | rupture top view of the buckling restraint brace, (B) is the fracture | rupture side view. FIG. 3 is an enlarged view of a part III in FIG. (A) is a top view of the buckling restraint brace which concerns on 1st Embodiment of this invention, (B) is the same side view. (A) is the fracture | rupture top view of the same buckling restraint brace, (B) is the fracture | rupture side view. 4A is an enlarged sectional view taken along the arrow VIa-VIa in FIG. 4A, FIG. 4B is an enlarged sectional view taken along the line VIb-VIb in FIG. 4A, and FIG. 4C is VI c in FIG. FIG. It is an enlarged view of the VII part of FIG. 4 (B). (A) is a top view of the buckling restraint brace which concerns on other embodiment of this invention, (B) is the same side view. It is an enlarged view of the IX part of FIG.

A proposal example as a basis of the present invention will be described with reference to FIGS. This buckling restraint brace has a plate-like core material 1 and a pair of restraint materials 2 and 2 arranged opposite to each other along both surfaces of the core material 1, and the core material 1 is attached to both ends of the building frame. A joint portion 3 to be joined to (not shown) is provided so as to protrude from the restraining materials 2 and 2 in the longitudinal direction. The core material 1 is a strip-shaped flat steel plate, and is made of a steel material such as an SN material (rolled steel material for building structures) or a LYP material (low yield point steel material). The restraining material 2 is formed of a square pipe or the like.

  This buckling restraint brace is a buckling restraint brace using a square pipe having the above-described configuration, in which the joint portions 3 at both ends of the core material 1 are projected to both sides in the width direction from the other portions of the core material 1. The shape having 3a and 3a is wider than the constraining material 2, and reinforcing ribs 4 are provided at both ends in the width direction of the joint portion 3 having the wider width. In detail, the core material 1 is formed such that the intermediate portion 1b, which is a portion other than the joint portion 3, has a constant width, and the joint portions 3 at both ends have a constant width shape that spreads on both sides of the intermediate portion 1b. Yes. The shape of the edge 3aa on the center side in the longitudinal direction of the core material in the protruding portion 3a of the core material 1 is an arc shape gradually spreading from the intermediate portion 1b which is the other part of the core material 1. ing. Each joint portion 3 is provided with a plurality of bolt insertion holes 11 through which bolts (not shown) to be joined to the housing are inserted.

  The reinforcing rib 4 is made of, for example, a strip-shaped flat steel plate, and is joined to the joining portion 3 by attaching the end surface in the width direction of the joining portion 3 of the core material 1 along the center in the width direction. The pair of reinforcing ribs 4 and the joint portion 3 form an H-shaped cross section. The length range in which the reinforcing ribs 4 are provided is such that the center side of the core material 1 reaches the edge of the joint portion 3 and the end side of the core material 1 reaches a position that does not reach the edge of the joint portion 3 slightly. Yes.

  The length of the constraining material 2 is formed so as to sandwich a part of the length range of the joint portion 3 of the core material 1 which is wide. It is preferable that the restraining material 2 has a length that sandwiches the core material 2 up to the maximum length range in a range that does not affect the joining by the joining portion 3. In the example shown in the drawing, a length range of 1/3 or more and 1/2 or less of the joint 3 is sandwiched between the restraining materials 2.

  As shown in FIG. 1 (C), the width direction stiffener 6 across the restraining materials 2 and 2 is joined to the width surfaces on both sides of the pair of restraining materials 2 and 2 by a welded portion 12, The core material 1 is interposed between the stiffeners 6 and 6. The width-direction stiffener 6 is slightly narrower than the combined width of the two restraining materials 2, 2 and has a strip shape extending in the longitudinal direction of the restraining material 2. The length of the width direction stiffener 6 is slightly shorter than that of the restraining material 2 and is such that both ends do not reach the edge of the restraining material 2, and a section W in the vicinity of the joint portion 3 in the core material 1 (see FIG. 1). , 3 is a non-stiffening section W that is not stiffened by the width direction stiffener 6.

  A pair of reinforcing plates 5 made of steel plates are provided between the reinforcing ribs 4, 4 at both ends in the width direction of the joint portion 3 of the core material 1 so as to sandwich the pair of restraining materials 2, 2. . Thereby, it is prevented that the edge part of the restraint material 2 opens to an out-of-plane direction, and the edge part of a buckling restraint brace is damaged.

  As shown in FIG. 2 (B), a pin-shaped detent protrusion 9 that protrudes from both sides of the core 1 is provided at the center in the longitudinal direction of the core 1 and in the center in the width direction. 9 is inserted into the hole 10 provided in the inner wall surface of the constraining member 2 made of a square pipe as shown in FIG. 1C when the buckling constraining brace is assembled. The slip prevention protrusion 9 is made of a steel material such as a steel rod, and is inserted into a hole (not shown) provided in the core material 1 or abutted against the surface of the core material 1 to be joined.

  Further, as shown in FIG. 2 (B), the portion sandwiched between the restraining materials 2 and 2 of the core material 1 is located on both sides in the length direction of the core material 1 with respect to the deviation preventing projections 9 and two Intermediate slits 7 for adjusting the proof stress are provided. In each intermediate slit 7, an internal deformation preventing material 8 made of a steel material or the like serving as a spacer is inserted so as to be movable relative to the intermediate slit 7 in the longitudinal direction. The internal deformation preventing material 8 is interposed between the pair of restraining materials 2 and 2, and the position is restricted by the restraining materials 2 and 2 with respect to the depth direction of the intermediate slit 7.

  According to the buckling restrained brace having the above-described configuration, since the reinforcing ribs 4 are provided at both ends in the width direction of the joint portion 3 of the core material 1, the load that ensures the strength of the joint portion 3 and causes large deformation is applied. Even if it acts on the joint 3, damage is prevented. Further, the joining portion 3 is made wider than the constraining material 2 as a shape having a portion 3a projecting in the width direction from the other portion of the core material 1, and the reinforcing rib 4 is provided on the projecting portion 3a. Therefore, even if a large deformation occurs in the core material 1 due to the gap d (FIG. 3) between the reinforcing rib 4 and the constraining material 2 generated in the protruding portion 3a, the reinforcing rib 4 is restrained by the deformation. Therefore, the joint 3 is prevented from being damaged by interference.

  Since the protruding portion 3a of the joint portion 3 of the core material 1 has an arcuate shape that gradually expands the shape of the edge 3aa on the center side, it is possible to relieve the breakage while being a locally protruding shape. .

  The constraining material 2 is formed to have a length that sandwiches a length range of a part of the wide joint portion 3 of the core material 1 and does not affect the joining by the joint portion 3. Therefore, the deformation of the core material 1 in the weak axis direction is suppressed by the sandwiched restraining materials 2 and 2, and a high buckling prevention function can be obtained. As described above, the “weak axis direction of the core material 1” refers to the plate thickness direction of the flat core material 1, and the width direction of the core material 1 is referred to as the “strong axis direction of the core material 1”.

  Further, the restraining material 2 is provided with a width direction stiffener 6, but this width direction stiffener 6 does not stiffen the portion in the vicinity of the joint 3 in the core material 1, but near both ends of the core material 1. A non-stiffening section W with respect to the strong axis direction is formed. Therefore, a bending hinge is formed in the buckling restrained brace in the strong axial direction non-stiffening section W during large deformation, thereby preventing the restraining material 2 from being damaged due to bending or axial force entering the restraining material 2. .

  In particular, as described above, the constraining material 2 has a length that sandwiches a part of the length range of the joint portion 3 of the core material 1, and the core material 1 is maximized within a range that does not affect the joining by the joint portion 3. Since the length sandwiched to the length range and the portion of the core material 1 in the vicinity of the joint portion 3 is the non-stiffening section W, deformation in the weak axis direction is restrained by sandwiching the core material 1 during large deformation. The material 2 is restrained, plays a role of a bending hinge in the non-stiffening section W in the strong axis direction, and withstands a large deformation, for example, a deformation of 1/15 or more by causing interlayer deformation near the joint 3. It becomes possible to satisfy. Thereby, the performance which bears the deformation | transformation of 1/15 requested | required of the industrialized house is acquired.

In this proposed example , the restraint material 2 is a square pipe. Therefore, a high stiffening effect is obtained by the pipe-shaped cross-sectional shape and the steel material, which is required as compared with the restraint material filled with mortar or the like. The weight can be reduced by the ratio of the stiffening effect. This weight reduction leads to an improvement in workability on site.

Further, in this proposed example , since the intermediate slit 7 is provided in the core material 1, the intermediate slit 7 can have a function of adjusting the yield strength and rigidity of the buckling restrained brace. For example, the proof stress can be adjusted by designing the width of the intermediate slit 7 and the rigidity can be adjusted by designing the length of the intermediate slit 7. Many conventional buckling-restrained braces are provided with a dog-bone-shaped notch in the center of the core material. However, this often causes local destruction of the buckling-restraining material and loses its function. On the other hand, when the intermediate slit 7 is provided at the center, the force in the out-of-plane direction caused by the buckling of the core material 1 is efficiently transmitted to the restraint material 2 to prevent local destruction of the restraint material. Works effectively. In this proposed example , as described above, the two intermediate slits 7 are provided on both sides in the longitudinal direction with the centering of the protrusion 9 provided at the center of the core material 1, so that the seat of the core material 1 is provided. The force in the out-of-plane direction caused by the bending can be efficiently transmitted to the restraint material 2, and local destruction of the restraint material 2 can be prevented.

  In addition, in order to prevent the core material 1 from being deformed outward in the strong axis direction, the intermediate slit 7 may be formed in such a manner that one part is connected to each other and divided into a plurality of two or more. The core material 1 is prevented from being deformed inward in the strong axis direction by the internal deformation preventing material 8 inserted into the intermediate slit 7.

4 to 7 show a first embodiment of the present invention. In the proposed example , the unstiffened section W at the end becomes the breaking point at the final stage, but this embodiment is intended to further improve the earthquake resistance by improving the detail of the end. In this embodiment, other than the matters to be specifically described are the same as in the proposed example .

  In this embodiment, the end E in the longitudinal direction of the width direction stiffener 6 is set to an intermediate position, for example, a center position, of the longitudinal width of the core of the reinforcing plate 5. An end slit 13 into which the joint 3 is fitted is provided up to the end of the non-stiffening section W. Note that the “intermediate position” here refers to a position within the width of the reinforcing plate 5, not the center.

In the case of this embodiment, the range other than the joint portion 3 in the length of the width direction stiffener 6 provided with the end slit 13 is the strong axis direction (core material) of the core material 1 by the width direction stiffener 6. The buckling in the width direction is an unstiffened section W that is not constrained. However, in the non-stiffening section W where the slit 13 is present, the restraint member 2 is reinforced in the weak axis direction.
Thus, by not restraining the strong axis direction (core material width direction) in the non-stiffening section W, it is possible to prevent local buckling in the core material weak axis direction while corresponding to the interlayer deformation 1/15. it can.

The effects in this embodiment are summarized and shown below.
・ By devising the detail of the end, stable seismic performance can be obtained without buckling up to large deformation exceeding 1/30.
The buckling of the core material 1 is prevented by the restraint material 2 and local deformation of the end of the restraint material 2 is prevented by the reinforcing plate 5 provided at the end of the core material 1. That is, the core material 1 and the restraint material 2 are configured to prevent deformation of each other.
A non-stiffening section W is provided at the end of the core material 1 so that a bending hinge can be formed during large deformation. This prevents the restraint material 2 from being broken due to bending or axial force entering the restraint material 2.
An intermediate slit 7 is provided in the center of the core material 2 to provide a function for adjusting the proof stress and rigidity. The width of the intermediate slit 7 has a function to adjust the proof stress and the length to adjust the rigidity.
The provision of the intermediate slit 7 at the center effectively transmits an out-of-plane force caused by buckling of the core material 1 to the restraint material 2 and effectively functions to prevent local destruction of the restraint material 2.
The unstiffened section W at the end of the core material is reinforced by extending the width direction stiffener 6 made of a plate that joins the restraining materials 2 and 2 to the position of the reinforcing plate 5 at the end.
The internal deformation preventing material 8 that is a spacer is one or a plurality of plates, and the thickness is made thicker than that of the core material 1, thereby ensuring a gap between the core material 1 and the restraint material 2. Thereby, unbond materials, such as a butyl rubber, conventionally required can be omitted.

  8 and 9 show still another embodiment. In this embodiment, in the embodiment shown in FIGS. 4 to 7, the reinforcing plate 5 is extended to the center side of the core material, and the longitudinal width of the reinforcing plate 5 is set to a width that covers the entire unstiffened section W. It is a thing. That is, the end 5a on the center side of the reinforcing plate 5 in the longitudinal direction of the core material is also positioned at the center side of the core material with respect to the non-stiffening section W. The end slit 13 into which the joint portion 3 of the core material 1 is fitted allows the entire range of the slit length to enter the length range of the reinforcing plate 5. However, in this example, the length of the end slit 13 is shorter than the examples of FIGS.

  In the case of this embodiment, the reinforcing plate 5 is extended to the center side of the core material, and the width of the core material in the longitudinal direction of the reinforcing plate 5 is set to a width that fits the entire non-stiffening section W. In addition, since the entire unstiffened section W is hidden by the reinforcing plate 5, the appearance of the buckling restrained brace becomes beautiful. Other configurations in this embodiment are the same as those in the embodiment shown in FIGS.

  In each of the above embodiments, the constraining material 2 is constituted by a single square pipe, but each constraining material 2 is a steel material in which a plurality of square pipes are joined, or a steel material in which a plurality of square pipes, section steels, etc. are joined. Alternatively, a combination of steel and mortar or concrete may be used.

DESCRIPTION OF SYMBOLS 1 ... Core material 2 ... Restraining material 3 ... Joint part 3a ... Overhang | projection part 3aa ... End edge 3b ... Intermediate | middle part 4 ... Reinforcement rib 5 ... Reinforcement plate 6 ... Width direction stiffener 7 ... Intermediate slit 9 ... Missing protrusion protrusion 8 ... internal deformation prevention material 13 ... end slit d ... gap E ... end W ... non-stiffening section in the strong axis direction

Claims (6)

A buckling restraint having a plate-shaped core material and a pair of constraining materials arranged opposite to each other along both sides of the core material, and the core material is provided at both ends with joints to be joined to the building frame. In braces,
The joint portion of the core material is shaped to have a portion that protrudes in the width direction from the other portions of the core material, and is wider than the constraining material, and is reinforced at both ends in the width direction of the wide joint portion. only set the ribs, said pair of over restraining member, the width direction stiffener to constrain the deformation in the width direction of the core material provided, the width direction stiffeners, around the joint portions in the core material A buckling-restrained brace in which the end portion slit is formed as a non-stiffening section without being constrained in the width direction, and an end slit into which the joint portion of the core member is fitted is provided in the width-direction stiffener. . A buckling restraint having a plate-shaped core material and a pair of constraining materials arranged opposite to each other along both sides of the core material, and the core material is provided at both ends with joints to be joined to the building frame. In braces,
The joint portion of the core material is shaped to have a portion that protrudes in the width direction from the other portions of the core material, and is wider than the constraining material, and is reinforced at both ends in the width direction of the wide joint portion. Provide ribs,
A width direction stiffening material is provided across the pair of restraining materials to restrain the deformation in the width direction of the core material, and the width direction stiffening material has a portion of the core material in the vicinity of the joint. Without stiffening in the direction,
Reinforcing plates are provided at both side positions sandwiching the pair of restraining materials across the reinforcing ribs at both ends in the width direction, and the longitudinal ends of the width direction stiffeners are arranged in the longitudinal width of the core of the reinforcing plate. A buckling restrained brace provided with an end slit into which the joint portion of the core material fits in the width direction stiffener up to the non-stiffening section. The buckling constraining brace according to claim 2 , wherein a width and a position of the reinforcing plate in the longitudinal direction of the core member are set to a width and a position in which the entire unstiffened section is accommodated. The buckling restraint brace according to any one of claims 1 to 3, wherein the restraint member is formed to have a length sandwiching a length range of a part of the widened joint portion of the core member. Buckled restrained brace. The buckling restrained brace according to any one of claims 1 to 4, wherein the shape of the edge on the center side in the longitudinal direction of the core material in the protruding portion of the joint portion of the core material is the A buckling-restrained brace that has an arc shape that gradually expands from other parts. The buckling restrained brace according to any one of claims 1 to 5 , wherein the restraining material is a square pipe.

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