JP7829633B2 - Buckling-restrained brace - Google Patents

Description

This invention relates to a buckling-restrained brace.

Conventionally, buckling-restrained braces have been used as reinforcing materials for structures. In buckling-restrained braces, the core material receiving axial force is restrained from the outer periphery by restraining members, preventing deformation and buckling in directions other than the longitudinal direction of the core material, while allowing it to undergo plastic deformation. Using buckling-restrained braces improves the seismic resistance and vibration control performance of structures.

When a longitudinal compressive force is applied to the core material, the core material displaces longitudinally, potentially causing interference between the core material and the hardening agent (filler) filled between the core material and the restraining member. In the buckling-restrained brace described in Patent Document 1, a buffer member is provided between the core material and the hardening agent to prevent interference between them.

Japanese Patent Publication No. 2016-075037

When a compressive force is applied to the core material in the longitudinal direction, the core material expands in the thickness and width directions due to Poisson's ratio. In the structure described in Patent Document 1, this expansion of the core material may cause interference between the core material and the hardening agent.

This invention has been made in view of the circumstances described above, and aims to provide a buckling-restrained brace that can prevent interference between a member and a filler when a longitudinal compressive force is applied to the member.

<1> A buckling-restrained brace according to a first aspect of the present invention comprises a longitudinally extending member including a first portion and a second portion provided on the end side of the first portion, a restraining member covering the outer circumference of the member, a filler filling the space between the member and the restraining member, a buffer member, and an unbonded material covering the member, wherein the buffer member is provided on at least one of the front and back surfaces of the first portion in the portion of the member where the rigidity is relatively low.

<2> A buckling-restrained brace according to a second aspect of the present invention comprises a longitudinally extending member including a first portion and a second portion provided on the end side of the first portion, a restraining member covering the outer circumference of the member, a filler filling the space between the member and the restraining member, a cushioning member, and an unbonded material covering the member, wherein the cushioning member is provided on at least one of the front and back surfaces of the first portion in the portion where the stiffening by the second portion is insufficient.

<3> In the buckling-restrained brace according to <1> or <2> above, the member includes an inclined portion that slopes toward the central axis of the buckling-restrained brace as it moves from the end of the member toward the center of the member, and the cushioning member is positioned between the filler and the inclined portion. The sum of the length of the cushioning member in either the thickness direction or the width direction of the first portion, and the length of the unbonded material in either direction, may be greater than the length of the inclined portion in either direction.

<4> In the buckling-restrained brace described in <3> above, the buffer member is a core-side buffer member positioned between the filler and the first portion, and the length of the buffer member is the length of either the thickness direction or the width direction of the first portion, which is the length of the core-side buffer member. The inclined portion is provided on the first portion.

<5> In the buckling-restrained brace according to <3> above, the second portion may be provided on at least one of the front and back surfaces of the first portion, the cushioning member may be a stiffening member-side cushioning member positioned between the filler and the second portion, the length of the cushioning member being the length of either the thickness direction or the width direction of the first portion and the length of the stiffening member-side cushioning member, and the inclined portion may be provided on the second portion.

<6> In a buckling-restrained brace relating to any one of <3> to <5> above, a configuration may be adopted in which the length of one of the aforementioned components, which is the length of the cushioning member, and the length of the other aforementioned component, which is the length of the inclined portion, are substantially the same.

<7> In the buckling-restrained brace described in <6> above, a configuration may be adopted in which the length of one of the cushioning members is longer than the length of the unbonded material.

<8> In the buckling-restrained brace described in <7> above, a configuration may be adopted in which the longitudinal direction of the unbonded material and the longitudinal direction of the cushioning member are substantially parallel.

<9> In the buckling-restrained brace described in <8> above, a configuration may be adopted in which the length of one of the unbonded members is substantially constant along the longitudinal direction of the first portion.

<10> In a buckling-restrained brace relating to any one of <1> to <9> above, the unbonded material may be configured to cover the cushioning member and the member.

<11> In a buckling-restrained brace relating to any one of <3> to <9> above, the unbonded material may be provided between the cushioning member and the inclined portion, and may also cover the member.

According to the present invention, interference between the member and the filler can be prevented when a longitudinal compressive force is applied to the member.

This is a view of the buckling-restrained brace according to the first embodiment, along the thickness direction of the core material. This is a view of the buckling-restrained brace according to the first embodiment, along the width direction of the core material. This is an enlarged view of part A in Figure 1. This is an enlarged view of part B in Figure 2.

(First Embodiment)
A buckling-restrained brace according to one embodiment of the present invention will be described below with reference to the drawings.
The buckling-restrained brace 1 shown in Figures 1 and 2 is attached to a structure. The buckling-restrained brace 1 is used, for example, to reinforce a structure consisting of columns and beams in a building.

The buckling-restrained brace 1 comprises a core material 10, a stiffening member 20, a restraining member 30, a hardening agent 31 (filler), an unbonding material 32, a core material-side buffer member 40, a stiffening member-side buffer member 50, and a weld-side buffer member 60.

The core material 10 is a flat plate made of steel. The core material 10 reinforces the building by being attached to the building structure at both ends. As shown in Figure 1, the core material 10 comprises a narrow section 11, a wide section 12, a width-changing section 13, and a projection 14.

The narrow section 11 is located in the center of the core material 10 in the longitudinal direction. The wide sections 12 are located at both ends of the core material 10 in the longitudinal direction. The width of the wide section 12, which is the width of the core material 10 in the board width direction, is wider than the width of the narrow section 11, which is the width of the core material 10 in the board width direction. The length of the wide section 12, which is the length along the longitudinal direction of the core material 10, is shorter than the length of the narrow section 11, which is the length along the longitudinal direction of the core material 10.
In the core material 10, the center in the longitudinal direction is a narrow portion 11, and the ends in the longitudinal direction are wide portions 12. As a result, the center in the longitudinal direction of the core material 10 (narrow portion 11) becomes a region that is easily plasticized, and the plasticization region is limited to the center.

As shown in Figure 1, the width-changing section 13 is the boundary region between the wide section 12 and the narrow section 11. The width of the width-changing section 13, along the width direction of the core material 10, changes along the longitudinal direction. The width of the width-changing section 13 narrows from the longitudinal end of the core material 10 (i.e., the wide section 12 side) towards the longitudinal center of the core material 10 (i.e., the narrow section 11 side). Viewed along the thickness direction, the side surface 13c (see Figure 3) of the width-changing section 13 in the width direction is a straight line inclined with respect to the longitudinal direction. The width-changing section 13 absorbs, for example, the additional bending moment acting on the core material 10.

The wide section 12 includes a first wide section 12a located at one end in the longitudinal direction of the core material 10, and a second wide section 12b located at the other end in the longitudinal direction of the core material 10. The width-changing section 13 includes a first width-changing section 13a located between the first wide section 12a and the narrow section 11, and a second width-changing section 13b located between the second wide section 12b and the narrow section 11. The width of the first width-changing section 13a narrows as it moves from one end in the longitudinal direction of the core material 10 towards the center in the longitudinal direction of the core material 10. The width of the second width-changing section 13b narrows as it moves from the other end in the longitudinal direction of the core material 10 towards the center in the longitudinal direction of the core material 10.

The projection 14 is provided in the center of the core material 10 in the longitudinal direction. The projection 14 protrudes from the side surface of the core material 10 in the width direction. The projection 14 is provided on both sides of the core material 10 in the width direction.

The stiffening member 20 is a plate-shaped member made of steel plate. The stiffening member 20 reinforces both ends of the core material 10, preventing the core material 10 from bending in the thickness direction. The stiffening member 20 is joined to the core material 10 by welding. A welded joint W is formed at the joint between the core material 10 and the stiffening member 20.

The stiffening member 20 includes a first stiffening member 21 and a second stiffening member 22.
The first stiffening member 21 is attached to the first wide portion 12a. The first stiffening member 21 is provided on the front and back surfaces of the first wide portion 12a (i.e., the surfaces facing the thickness direction of the core material 10). The core material 10 and the first stiffening member 21 have a cross-shaped cross section.
The second stiffening member 22 is attached to the second wide portion 12b. The second stiffening member 22 is provided on the front and back surfaces of the second wide portion 12b (i.e., the surfaces facing the thickness direction of the core material 10). The core material 10 and the second stiffening member 22 have a cross-shaped cross section.

The first stiffening member 21, the second stiffening member 22, the first wide section 12a, and the second wide section 12b each have bolt holes (not shown). The buckling-restrained brace 1 is attached to the structure by bolts (not shown) inserted into the bolt holes.

The restraining member 30 is cylindrical. For example, the restraining member 30 is a rectangular steel pipe. Alternatively, the restraining member 30 may be a cylindrical steel pipe.

The restraining member 30 covers the outer circumference of the core material 10. The length of the restraining member 30 along the longitudinal direction of the core material 10 is shorter than the total longitudinal length of the core material 10. The length of the restraining member 30 is longer than the length of the narrow portion 11. As a result, the wide portion 12 of the core material 10 protrudes outward from the restraining member 30.

The hardening agent 31 is filled between the core material 10 and the restraining member 30. For example, the material of the hardening agent 31 is concrete or mortar. To prevent the hardening agent 31 from leaking out from the ends of the restraining member 30, both ends of the restraining member 30 are sealed with lids (not shown).

The unbonding material 32 is provided between the core material 10 and the stiffening member 20 and the hardening agent 31. The unbonding material 32 prevents the core material 10 and the stiffening member 20 from adhering to each other. The unbonding material 32 allows the core material 10 to move relative to the hardening agent 31.

In this embodiment, the unbonded material 32 covers the core material 10, the stiffening member 20, the core material-side cushioning member 40, the stiffening member-side cushioning member 50, and the welded-side cushioning member 60. The unbonded material 32 is formed, for example, by bonding a sheet-like material to the outer surfaces of the core material 10, the stiffening member 20, the core material-side cushioning member 40, the stiffening member-side cushioning member 50, and the welded-side cushioning member 60. The unbonded material 32 may also be formed by applying a paint-like material to the outer surfaces of the core material 10, the stiffening member 20, the core material-side cushioning member 40, the stiffening member-side cushioning member 50, and the welded-side cushioning member 60.

The presence of the unbonding material 32 allows the hardening agent 31 to hold the core material 10 so that it can move relative to the restraining member 30 in the longitudinal direction, preventing the axial force of the core material 10 from being transmitted to the restraining member 30. The restraining member 30 and the hardening agent 31 restrict deformation of the core material 10 in directions other than the longitudinal direction.

As shown in Figures 1 and 3, the core material-side buffer member 40 is positioned between the hardening agent 31 and the width-changing portion 13. The core material-side buffer member 40 is positioned adjacent to the width-changing portion 13 in the longitudinal direction.
When a longitudinal compressive force is applied to the core material 10 due to an earthquake or the like, the width-changing portion 13 is displaced toward the longitudinal center of the core material 10. At this time, the core material-side buffer member 40 is pressed by the width-changing portion 13 and contracts, absorbing the displacement of the width-changing portion 13. This prevents interference between the width-changing portion 13 and the hardening agent 31, preventing damage to the core material 10 and preventing the axial force of the core material 10 from being transmitted to the hardening agent 31.

The core material-side buffer member 40 includes a first buffer member 41 and a second buffer member 42. The first buffer member 41 is positioned between the hardening agent 31 and the first width-changing portion 13a. The second buffer member 42 is positioned between the hardening agent 31 and the second width-changing portion 13b. As shown in Figure 1, the shapes of the first buffer member 41 and the second buffer member 42 are symmetrical with respect to a first center line C1 passing through the center of the longitudinal direction of the core material 10, when viewed along the thickness direction of the core material 10.

As shown in Figure 3, the outer shape of the core material-side buffer member 40 is a parallelogram shape, viewed along the thickness direction of the core material 10, having a first side 40a (contact side), a second side 40b, a third side 40c (opposing side), and a fourth side 40d. The first side 40a contacts the side surface 13c of the width-changing section 13. The third side 40c opposes the first side 40a. The first side 40a and the third side 40c are inclined with respect to the longitudinal direction of the core material 10. The second side 40b contacts the side surface in the width direction of the narrow section 11. The fourth side 40d opposes the second side 40b. The second side 40b and the fourth side 40d are parallel to the longitudinal direction of the core material 10.

The material of the core-side buffer member 40 is appropriately selected from materials that satisfy the following (1) to (3). That is, (1) The core-side buffer member 40 has rigidity that allows it to maintain its shape when filled with the hardening agent 31. (2) During an earthquake greater than Level 1, the volume of the core-side buffer member 40 becomes 0.1 times or less the contraction of the core material 10. (3) The size of the core-side buffer member 40 when it contracts during an earthquake greater than Level 1 is 0.2 times or less the size of the core-side buffer member 40 before contraction. For example, the material of the core-side buffer member 40 is foam. Foam includes foamed plastics such as expanded polystyrene. Examples of expanded polystyrene include extruded expanded polystyrene and polystyrene foam.
Regarding earthquake levels, based on the description in the "2020 Commentary on Technical Standards Related to the Structure of Buildings" (edited by the Building Administration Information Center and the Japan Building Disaster Prevention Association; p. 71), the following definitions are established: Level 1 is defined as an earthquake that occurs rarely (approximately once every 50 years). A Level 1 earthquake is highly likely to occur at least once during the lifespan of a building. Level 2 is defined as an earthquake that occurs extremely rarely (approximately once every 500 years). Furthermore, Level 3 is defined as a maximum earthquake motion that is larger in magnitude than Level 2 ground motion.

As shown in Figure 3, the length of the core material-side buffer member 40 along the longitudinal direction of the core material 10 is defined as L1. As shown in Figure 1, the length of the narrow section 11 along the longitudinal direction of the core material 10 (i.e., the length between the first width change section 13a and the second width change section 13b) is defined as L2. The length L1 of the core material-side buffer member 40 is set as follows. That is, as the seismic standards in this disclosure, the maximum inter-story drift angle of the building during a Level 1 earthquake is set to 1/200 or less, and the maximum inter-story drift angle of the building during a Level 2 earthquake is set to 1/100 or less. In this case, when a longitudinal compressive force is applied to the core material 10, the length L2 of the narrow section 11 will shrink by 0.25% (i.e., 1/400) during a Level 1 earthquake and by 0.50% (i.e., 1/200) during a Level 2 earthquake. The length L1 of the core material-side buffer member 40 is set considering a safety factor of 2 for this shrinkage. For example, the length L1 of the core material-side cushioning member 40 is 0.005 times or more and 0.015 times or less of the length L2 of the narrow section 11.

As shown in Figure 4, the thickness of the core material-side cushioning member 40 is defined as T1, where T1 is the thickness of the core material 10 in the thickness direction, and T2 is the thickness of the core material 10. The thickness T1 of the core material-side cushioning member 40 is greater than the thickness T2 of the core material 10. For example, the thickness T1 of the core material-side cushioning member 40 is 1.02 times or more and 1.1 times or less the thickness T2 of the core material 10.
When a compressive force is applied to the core material 10 in the longitudinal direction, the core material 10 expands in the thickness direction and width direction according to Poisson's ratio. By making the thickness T1 of the core material-side buffer member 40 thicker than the thickness T2 of the core material 10, even if the core material 10 expands in the thickness direction, the expansion of the core material 10 can be absorbed by the core material-side buffer member 40, preventing the core material 10 from interfering with the hardening agent 31.

As shown in Figures 2 and 4, the stiffening member-side buffer member 50 is positioned between the hardening agent 31 and the stiffening member 20. The stiffening member-side buffer member 50 is positioned adjacent to the stiffening member 20 in the longitudinal direction.
Since the stiffening member 20 is joined to the core material 10, when a longitudinal compressive force is applied to the core material 10 due to an earthquake or the like, the stiffening member 20 also displaces toward the longitudinal center of the core material 10. At this time, the stiffening member-side buffer member 50 is pressed by the stiffening member 20 and contracts, absorbing the displacement of the stiffening member 20. This prevents interference between the stiffening member 20 and the hardening agent 31, and prevents damage to the stiffening member 20.

The stiffening member-side buffer member 50 includes a third buffer member 51 and a fourth buffer member 52. The third buffer member 51 is positioned between the hardening agent 31 and the first stiffening member 21. The fourth buffer member 52 is positioned between the hardening agent 31 and the second stiffening member 22. As shown in Figure 2, the shapes of the third buffer member 51 and the fourth buffer member 52 are symmetrical with respect to a second center line C2 passing through the center of the longitudinal direction of the core material 10, when viewed along the plate width direction of the core material 10 (i.e., the plate thickness direction of the stiffening member 20).

As shown in Figure 4, the outer shape of the stiffening member-side buffer member 50 is a parallelogram shape, having a first side 50a, a second side 50b, a third side 50c, and a fourth side 50d, when viewed along the plate width direction of the core material 10 (i.e., the plate thickness direction of the stiffening member 20). The first side 50a contacts the side surface 20a of the stiffening member 20. The third side 50c faces the first side 50a. The first side 50a and the third side 50c are inclined with respect to the longitudinal direction of the core material 10. The fourth side 50d faces the second side 50b. The second side 50b and the fourth side 50d are parallel to the longitudinal direction of the core material 10.

The material of the stiffening member-side buffer member 50 is selected in the same way as the material of the core material-side buffer member 40. For example, the material of the stiffening member-side buffer member 50 is foam.
The length of the stiffening member-side buffer member 50, along the longitudinal direction of the core material 10, is defined as L3. The length L3 of the stiffening member-side buffer member 50 is set in the same way as the length L1 of the core material-side buffer member 40. For example, the length L3 of the stiffening member-side buffer member 50 is 0.005 times or more and 0.015 times or less the length L2 of the narrow section 11.

As shown in Figure 3, the thickness of the stiffening member-side buffer member 50 is defined as T3, which is the thickness of the core material 10 in the plate width direction (i.e., the plate thickness direction of the stiffening member 20), and the plate thickness of the stiffening member 20 is defined as T4. The thickness T3 of the stiffening member-side buffer member 50 is greater than the plate thickness T4 of the stiffening member 20. For example, the thickness T3 of the stiffening member-side buffer member 50 is 1.02 times or more and 1.1 times or less the plate thickness T4 of the stiffening member 20.
Since the stiffening member 20 is joined to the core material 10, when a longitudinal compressive force is applied to the core material 10, a longitudinal compressive force is also applied to the stiffening member 20, causing the stiffening member 20 to expand in the plate thickness direction and plate width direction according to Poisson's ratio. By making the thickness T3 of the stiffening member-side buffer member 50 thicker than the plate thickness T4 of the stiffening member 20, even if the stiffening member 20 expands in the plate thickness direction, the expansion of the stiffening member 20 can be absorbed by the stiffening member-side buffer member 50, preventing the stiffening member 20 from interfering with the hardening agent 31.

The weld-side buffer member 60 is positioned between the hardening agent 31 and the weld W. The weld-side buffer member 60 is positioned adjacent to the weld W in the longitudinal direction. The width of the weld-side buffer member 60 is greater than the width of the weld line of the weld W.
When a longitudinal compressive force is applied to the core material 10 due to an earthquake or the like, the welded portion W also displaces toward the longitudinal center of the core material 10. At this time, the buffer member 60 on the welded portion side is pressed by the welded portion W and contracts, absorbing the displacement of the welded portion W. This prevents interference between the welded portion W and the hardening agent 31, and prevents damage to the welded portion W.

As described above, the buckling-restrained brace 1 according to this embodiment comprises a core material 10, a restraining member 30 covering the outer circumference of the core material 10, a hardening agent 31 filled between the core material 10 and the restraining member 30, and a core material-side buffer member 40. The core material 10 includes a width-changing portion 13 whose width narrows from the end of the core material 10 toward the center of the core material 10. The core material-side buffer member 40 is positioned between the hardening agent 31 and the width-changing portion 13. The thickness T1 of the core material-side buffer member 40 is greater than the plate thickness T2 of the core material 10.
The core material-side buffer member 40 prevents interference between the core material 10 and the hardener 31 due to longitudinal displacement of the core material 10 (width-changing portion 13) when longitudinal compressive force is applied to the core material 10 due to an earthquake or the like. Furthermore, when longitudinal compressive force is applied to the core material 10, the core material 10 expands in the thickness direction and width direction according to Poisson's ratio. By making the thickness T1 of the core material-side buffer member 40 thicker than the thickness T2 of the core material 10, even if the core material 10 expands in the thickness direction, the expansion of the core material 10 can be absorbed by the core material-side buffer member 40. Therefore, interference between the core material 10 and the hardener 31 due to expansion of the core material 10 in the thickness direction can also be prevented. In other words, the core material-side buffer member 40 can prevent interference between the core material 10 and the hardener 31 when longitudinal compressive force is applied to the core material 10. As a result, damage to the core material 10 and transmission of the axial force of the core material 10 to the hardening agent 31 can be prevented.

Furthermore, the outer shape of the core material-side cushioning member 40 is a parallelogram shape when viewed along the thickness direction of the core material 10, and includes a first side 40a and a third side 40c that are parallel to the longitudinal direction of the core material 10, and a second side 40b and a fourth side 40d that are inclined with respect to the longitudinal direction of the core material 10.
Furthermore, the first side 40a that contacts the width-changing portion 13 of the core material-side cushioning member 40 and the third side 40c of the core material-side cushioning member 40 that faces the first side 40a are parallel.
If the volume of the core material-side buffer member 40 is large, the buoyancy of the core material-side buffer member 40 when the hardening agent 31 is filled will be large. As a result, when the hardening agent 31 is filled, the core material-side buffer member 40 will float on the hardening agent 31, and the position of the core material-side buffer member 40 will be easily displaced. Also, if the surface area of the core material-side buffer member 40 is large, the pressure that the core material-side buffer member 40 receives from the hardening agent 31 when the hardening agent 31 is filled will be large, and the shape of the core material-side buffer member 40 may not be maintained, and the core material-side buffer member 40 may be compressed by the pressure of the hardening agent 31.
By making the outer shape of the core material-side buffer member 40 a parallelogram, it is possible to prevent interference between the hardening agent 31 and the core material 10 while preventing an increase in the volume and surface area of the core material-side buffer member 40. Therefore, when filling with the hardening agent 31, it is possible to suppress displacement of the core material-side buffer member 40 and maintain the shape of the core material-side buffer member 40, thereby improving workability.

Furthermore, a projection 14 is provided in the central part of the core material 10. The width-changing section 13 includes a first width-changing section 13a in which the width narrows as it moves from one end of the core material 10 toward the center of the core material 10, and a second width-changing section 13b in which the width narrows as it moves from the other end of the core material toward the center of the core material 10. The core material-side buffer member 40 includes a first buffer member 41 disposed between the hardening agent 31 and the first width-changing section 13a, and a second buffer member 42 disposed between the hardening agent 31 and the second width-changing section 13b. The shape of the first buffer member 41 and the shape of the second buffer member 42 are symmetrical.
Due to manufacturing errors in the buckling-restrained brace 1, the longitudinal displacement of the core material 10 when a longitudinal compressive force is applied to the core material 10 may be asymmetrical between the first width change section 13a side and the second width change section 13b side.
By providing the projection 14, relative movement of the core material 10 with respect to the hardening agent 31 is restricted at the center of the core material 10. As a result, when a longitudinal compressive force is applied to the core material 10, the core material 10 shrinks toward the center (projection 14), and the longitudinal displacement of the core material 10 becomes symmetrical between the first width change portion 13a side and the second width change portion 13b side. By making the shapes of the first buffer member 41 and the second buffer member 42 symmetrical, interference between the core material 10 and the hardening agent 31 when longitudinal compression is applied to the core material 10 can be prevented more effectively.

Furthermore, the core material-side buffer member 40 has the rigidity to maintain its shape when filled with the hardening agent 31, and the volume of the core material-side buffer member 40 becomes 0.1 times or less of the shrinkage of the core material 10 during earthquakes greater than Level 1 earthquakes.
The core material side cushioning member 40 is made of foam.
As a result, the shape of the core material-side buffer member 40 can be maintained when the hardening agent 31 is filled, and during an earthquake, the core material-side buffer member 40 can be contracted to more effectively prevent interference between the core material 10 and the hardening agent 31.

Furthermore, the buckling-restrained brace 1 further comprises a core material-side cushioning member 40 and an unbonded material 32 that covers the core material 10.
During construction, after placing the core-side cushioning member 40 on the core material 10, the core-side cushioning member 40 and the core material 10 are covered together with the unbonding material 32. This makes it easier to form the unbonding material 32. Also, because the core-side cushioning member 40 is covered with the unbonding material 32, it is possible to prevent the core-side cushioning member 40 from being compressed or moved by the pressure of the hardening agent 31 when the hardening agent 31 is filled in. Therefore, workability is improved.

Furthermore, the thickness T1 of the core material-side cushioning member 40 is 1.02 times or more and 1.1 times or less the plate thickness T2 of the core material 10.
As a result, even if the core material 10 expands in the thickness direction, the expansion of the core material 10 can be more reliably absorbed by the core material-side buffer member 40, and interference between the core material 10 and the hardening agent 31 can be more reliably prevented.

Furthermore, the width-changing section 13 includes a first width-changing section 13a in which the width narrows as it moves from one end of the core material 10 toward the center of the core material 10, and a second width-changing section 13b in which the width narrows as it moves from the other end of the core material 10 toward the center of the core material 10. The length L1 of the core material-side buffer member 40 is 0.005 times or more and 0.015 times or less the length L2 between the first width-changing section 13a and the second width-changing section 13b.
This makes it possible to more reliably prevent interference between the core material 10 and the hardening agent 31 when longitudinal compressive force is applied to the core material 10 due to earthquakes or the like. Furthermore, by setting the length L1 of the core material-side buffer member 40 to the above range, it is possible to prevent an increase in the volume and surface area of the core material-side buffer member 40 while ensuring the effect of preventing interference between the hardening agent 31 and the core material 10. Therefore, when filling with the hardening agent 31, it is possible to suppress displacement of the core material-side buffer member 40 and maintain the shape of the core material-side buffer member 40, improving workability.

The size of the core material-side buffer member 40 when it contracts during an earthquake greater than Level 1 is 0.2 times or less the size of the core material-side buffer member 40 before contraction.
This allows for more effective prevention of interference between the core material 10 and the hardening agent 31 during an earthquake by contracting the core material-side buffer member 40.

Furthermore, the buckling-restrained brace 1 further comprises a stiffening member 20 joined to the end of the core material 10, and a stiffening member-side buffer member 50 positioned between the hardening agent 31 and the stiffening member 20. The thickness T3 of the stiffening member-side buffer member 50 is greater than the plate thickness T4 of the stiffening member 20.
The stiffening member-side buffer member 50 prevents interference between the stiffening member 20 and the hardening agent 31 when longitudinal compressive force is applied to the core material 10 and the stiffening member 20 due to an earthquake or the like, by preventing the longitudinal displacement of the stiffening member 20. Furthermore, when longitudinal compressive force is applied to the core material 10 and the stiffening member 20, the stiffening member 20 expands in the plate thickness direction and plate width direction according to Poisson's ratio. By making the thickness T3 of the stiffening member-side buffer member 50 thicker than the plate thickness T4 of the stiffening member 20, even if the stiffening member 20 expands in the plate thickness direction, the expansion of the stiffening member 20 can be absorbed by the stiffening member-side buffer member 50, and interference between the stiffening member 20 and the hardening agent 31 due to the expansion of the stiffening member 20 in the plate thickness direction can be prevented.

Furthermore, the core material 10 and the stiffening member 20 are joined by welding. The buckling-restrained brace 1 further comprises a hardening agent 31 and a weld-side buffer member 60 positioned between the weld W of the core material 10 and the stiffening member 20.
The buffer member 60 on the welded side prevents interference between the welded W and the hardening agent 31 due to longitudinal displacement of the welded W when longitudinal compressive force is applied to the core material 10 and stiffening member 20 due to earthquakes or the like.

Furthermore, the present invention is not limited to the embodiments described above with reference to the drawings, and various modifications are conceivable within its technical scope.

For example, in the above embodiment, the unbonded material 32 covers the core material 10, the stiffening member 20, the core material side buffer member 40, the stiffening member side buffer member 50, and the welded portion side buffer member 60. However, the present invention is not limited to this. The unbonded material 32 may cover only the core material 10 and the stiffening member 20, without covering the core material side buffer member 40, the stiffening member side buffer member 50, and the welded portion side buffer member 60. In this case, the unbonded material 32 would be provided between the core material side buffer member 40 and the core material 10 (width variation portion 13), between the stiffening member side buffer member 50 and the stiffening member 20, and between the welded portion side buffer member 60 and the weld W.

In other words, the buckling-restraining brace 1 is provided between the core material-side buffer member 40 and the width-changing portion 13, and may further include an unbonded material 32 that covers the core material 10.
During installation, the core material 10 is covered with the unbonding material 32, and then the core material-side cushioning member 40 is placed on the core material 10 covered with the unbonding material 32. Since the core material-side cushioning member 40 is not covered with the unbonding material 32, it is possible to prevent the core material-side cushioning member 40 from being compressed by the unbonding material 32.

The core material 10 does not necessarily need to have a projection 14. The stiffening member 20 and the stiffening member-side cushioning member 50 may be omitted. The welded-side cushioning member 60 may also be omitted.

Furthermore, without departing from the spirit of the present invention, the components in the above embodiments may be replaced with well-known components as appropriate, and the above-described modifications may be combined as appropriate.

1. Buckling-restrained brace 10 Core material (first part)
11 Narrow section 12 Wide section 13 Width change section 13a First width change section 13b Second width change section 14 Projection 20 Reinforcement member (second part)
30 Restraining member 31 Hardening agent (filler)
32 Unbonded material 40 Core material side cushioning member 40a First side (contact side)
40c Third side (opposite side)
41 First buffer member 42 Second buffer member 50 Stiffening member side buffer member 60 Welded part side buffer member W Welded part

Claims (8)

A member extending in the longitudinal direction includes a core material and a stiffening member provided on the end side of the core material,
A restraining member covering the outer circumference of the aforementioned member,
A filler to be filled between the member and the restraining member,
Cushioning material and
A buckling-restrained brace comprising an unbonded material covering the aforementioned member,
The member includes an inclined portion that slopes toward the central axis of the buckling-restrained brace as it moves from the end of the member toward the center of the member,
The cushioning member is provided between the filler and the inclined portion on at least one of the front and back surfaces of the core material in the portion that expands in the thickness direction and width direction when a longitudinal compressive force is applied to the core material .
The sum of the length of the cushioning member in either the thickness direction or the width direction of the core material and the length of the unbonded material in either direction is longer than the length of the inclined portion in either direction.
The buckling-restrained brace is characterized in that the unbonded material covers the cushioning member and the member . A member extending in the longitudinal direction includes a core material and a stiffening member provided on the end side of the core material,
A restraining member covering the outer circumference of the aforementioned member,
A filler to be filled between the member and the restraining member,
Cushioning material and
A buckling-restrained brace comprising an unbonded material covering the aforementioned member,
The member includes an inclined portion that slopes toward the central axis of the buckling-restrained brace as it moves from the end of the member toward the center of the member,
The cushioning member is provided between the filler and the inclined portion on at least one of the front and back surfaces of the core material in the portion that expands in the thickness direction and width direction when a longitudinal compressive force is applied to the core material .
The sum of the length of the cushioning member in either the thickness direction or the width direction of the core material and the length of the unbonded material in either direction is longer than the length of the inclined portion in either direction.
The buckling-restrained brace is characterized in that the unbonded material is provided between the cushioning member and the inclined portion and covers the member . The cushioning member is a core material-side cushioning member that is placed between the filler and the core material.
The length of the cushioning member is the length of either the thickness direction or the width direction of the core material, and is the length of the cushioning member on the core material side.
The inclined portion is provided on the core material,
The buckling-restrained brace according to claim 1 or 2 . The stiffening member is provided on at least one of the front and back surfaces of the core material.
The cushioning member is a cushioning member on the stiffening member side, which is positioned between the filler and the stiffening member.
The length of the core material is the length of either the thickness direction or the width direction, and the length of the cushioning member is the length of either of the aforementioned lengths, and the length of the stiffening member-side cushioning member.
The inclined portion is provided on the stiffening member,
The buckling-restrained brace according to claim 1 or 2 . The length of one of the aforementioned lengths, which is the length of the cushioning member, and the length of the other aforementioned length, which is the length of the inclined portion, are substantially the same.
The buckling-restrained brace according to claim 1 or 2 . The length of the cushioning member is longer than the length of the unbonded material.
The buckling-restrained brace according to feature 5. The longitudinal direction of the unbonded material and the longitudinal direction of the cushioning member are substantially parallel.
The buckling-restrained brace according to feature 6. The length of the unbonded material is substantially constant along the longitudinal direction of the core material.
The buckling-restrained brace according to feature 7.