JP7577263B2 - Buckling Restrained Structural Materials - Google Patents

Description

Patent Act Article 30, Paragraph 2 applies. Publication name: 2020 Annual Convention (Kanto) Academic Lecture Abstracts and Architectural Design Presentation Abstracts, pp. 321-322 Publisher: Architectural Institute of Japan Publication date: July 20, 2020 Publication name: 2020 Annual Convention (Kanto) Academic Lecture Abstracts and Architectural Design Presentation Abstracts, pp. 363-364 Publisher: Architectural Institute of Japan Publication date: July 20, 2020 Publication name: 2020 Annual Convention (Kanto) Academic Lecture Abstracts and Architectural Design Presentation Abstracts, pp. 365-366 Publisher: Architectural Institute of Japan Publication date: July 20, 2020 Publication name: 2020 Annual Convention (Kanto) Academic Lecture Abstracts and Architectural Design Presentation Abstracts, pp. 367-368 Publisher: Architectural Institute of Japan Publication date: July 20, 2020 Publication name: 2020 Annual Meeting (Kanto) Academic Lecture Abstracts and Architectural Design Presentation Abstracts, pp. 369-370 Publisher: Architectural Institute of Japan Publication date: July 20, 2020 Publication name: 2020 Annual Meeting (Kanto) Academic Lecture Abstracts and Architectural Design Presentation Abstracts, pp. 371-372 Publisher: Architectural Institute of Japan Publication date: July 20, 2020

The present invention relates to buckling-restrained structural materials.

Conventionally, buckling restraint braces, such as those disclosed in Patent Document 1, have been used to be incorporated into structures to absorb vibration energy generated in the structures. The buckling restraint brace of Patent Document 1 comprises a steel pipe and a low-yield-point steel material placed inside the steel pipe, and concrete is filled between the steel pipe and the low-yield-point steel material, so that the concrete suppresses buckling of the low-yield-point steel material. However, because the buckling restraint brace of Patent Document 1 is made of steel pipes and concrete, it is very heavy, and there is a problem that it is difficult to transport to and handle at the construction site. In addition, because the buckling restraint brace of Patent Document 1 is made of steel, there is a problem that when it is incorporated into a wooden structure, etc., it will appear unbalanced.

To solve the above problems, wooden buckling restraint braces have been developed recently, as disclosed in Patent Document 2. Wooden buckling restraint braces are lightweight, making them easy to transport to and handle at the construction site. Furthermore, even when wooden buckling restraint braces are incorporated into wooden structures, they can prevent imbalances in appearance.

Japanese Patent Application Publication No. 6-57820 JP 2008-174932 A

In general, in a buckling restraint brace, when the core steel material tries to buckle, the restraining material resists the force that bulges outward from the steel material, thereby preventing the buckling of the steel material. However, in a wooden buckling restraint brace, the strength of the wooden restraining material is lower than that of metal or concrete, making it difficult to expect sufficient restraining force to restrain the buckling of the steel material. For example, in Patent Document 2, a gap is formed between the steel material and the restraining material, so that the force that bulges outward from the steel material increases when the steel material tries to buckle. If the force that bulges outward from the steel material increases in this way, the wooden restraining material may deform and may not be able to exert sufficient buckling restraint properties.

The present invention was developed in consideration of the above problems, and aims to provide a wooden buckling restraint structural material with excellent buckling restraint properties.

The buckling restraint structural material of the present invention is a buckling restraint structural material comprising a core material that extends along an extension direction and has a weak axis direction and a strong axis direction that are approximately perpendicular to the extension direction, and a wooden restraint material for restraining the buckling of the core material in the weak axis direction and the strong axis direction, characterized in that the restraint material comprises a pair of weak axis restraint materials provided on both sides of the core material in the weak axis direction so as to press and clamp the core material in the weak axis direction, and a pair of strong axis restraint materials provided on both sides of the core material in the strong axis direction so as to press and clamp the core material in the strong axis direction.

It is also preferable that the pair of weak axis restraint members are fixed to each other by a course thread screw extending in the weak axis direction so as to press and clamp the core material in the weak axis direction.

Furthermore, it is preferable that the pair of weak axis restraint members are provided on both sides of the weak axis direction of both the core material and the pair of strong axis restraint members, and the strong axis restraint members are formed to a size such that the length of the strong axis restraint members in the weak axis direction is shorter than the length of the core material in the weak axis direction.

It is also preferable that the buckling restraint structural member has a pair of side plates fixed to both sides of the weak axis restraint member in the strong axis direction, and that the pair of side plates are fixed to the pair of weak axis restraint members so as to compress the pair of strong axis restraint members in the strong axis direction between the pair of side plates and the core member.

Furthermore, it is preferable that the pair of weak axis restraint members are arranged on both sides of the weak axis direction of both the core material and the pair of strong axis restraint members, and the pair of strong axis restraint members are formed to a size such that the sum of the lengths of the core material and the pair of strong axis restraint members in the strong axis direction is longer than the length of the weak axis restraint member in the strong axis direction before the pair of side plates are fixed to the pair of weak axis restraint members.

It is also preferable that a self-adhesive is provided between the core material and the weak axis restraint material in the approximate center of the extension direction of the core material, which adheres the core material and the weak axis restraint material to each other, and that an unbond material is provided between the core material and the weak axis restraint material and the strong axis restraint material in both sides of the approximate center of the extension direction of the core material, which reduces the frictional force generated between the core material and the weak axis restraint material and the strong axis restraint material.

It is also preferable that the core material has wide portions provided at both ends in the extension direction and narrow portions provided between the wide portions at both ends in the extension direction, and the pair of weak axis restraint members are fixed to each other by fixing a pair of side plates to both side surfaces in the strong axis direction of the pair of weak axis restraint members at positions corresponding to the wide portions of the core material with fixing screws.

It is also preferable that the core material has wide sections provided at both ends in the extension direction and narrow sections provided between the wide sections at both ends in the extension direction, and that the pair of strong axis restraint members are provided over substantially the entire length of the narrow sections in the extension direction.

The present invention provides a wooden buckling-restrained structural material with excellent buckling restraint properties.

1 is an exploded perspective view of a buckling restraint structural member according to one embodiment of the present invention; FIG. 2 is a front view of a buckling restraint structural material according to one embodiment of the present invention, in which the self-adhesive and unbonding material are omitted. FIG. 3 is a side view of the buckling restraint structure of FIG. 2, with the self-adhesive and unbonded material omitted. FIG. 4 is a cross-sectional end view taken along line IV-IV in FIG. 2. 3 is a cross-sectional view taken along line VV in FIG. 2. FIG. 3 is a cross-sectional end view taken along line VI-VI in FIG. 2. FIG. 6 is a diagram showing a state before the side plate in FIG. 5 is fixed.

Below, a buckling restraint structural material according to one embodiment of the present invention will be described with reference to the attached drawings. However, the embodiment shown below is merely an example, and the buckling restraint structural material of the present invention is not limited to the following example.

As shown in Figs. 1 to 3, the buckling restrained structural member 1 of this embodiment comprises a core member 2 extending along the extension direction L, and a wooden restraining member 3 for restraining (suppressing) the buckling of the core member 2. The buckling restrained structural member 1 is used, for example, by connecting the core member 2 to a frame (not shown) to absorb vibration energy generated in the frame due to external disturbances such as earthquake motion or wind, or to improve the strength of the frame by resisting external forces received from the frame, or to suppress deformation of the frame. The buckling restrained structural member 1 can be used not only by connecting it diagonally to the frame as a brace or knee brace, but also by connecting it vertically or horizontally.

The core material 2 is a member that is connected to the frame and absorbs at least a portion of the vibration energy generated in the frame and/or resists external forces received from the frame. The core material 2 absorbs at least a portion of the vibration energy generated in the frame by yielding (plastically deforming) when it receives a tensile stress or compressive stress of a predetermined level or more in the direction in which the core material 2 extends (extension direction L). Since the core material 2 is prevented from buckling by the restraining member 3, it can stably repeat plastic deformation in the extension direction L and absorb relatively large vibration energy. Furthermore, the core material 2 resists external forces received from the frame by maintaining its shape within the elastic deformation range when it receives a tensile stress or compressive stress of a predetermined level or less in the extension direction of the core material 2. Since the core material 2 is prevented from buckling by the restraining member 3, it can maintain its strength in the extension direction of the core material 2 and resist relatively large external forces.

As shown in Figs. 1 to 3, the core material 2 has a weak axis direction W and a strong axis direction S that are substantially perpendicular to the extension direction L. The weak axis direction W means a direction in which the bending stiffness of the core material 2 is relatively small at least compared to the strong axis direction S, and for example, the bending stiffness of the core material 2 is the smallest among the directions substantially perpendicular to the extension direction L. The strong axis direction S means a direction in which the bending stiffness of the core material 2 is relatively large at least compared to the weak axis direction W, and for example, the bending stiffness of the core material 2 is the largest among the directions substantially perpendicular to the extension direction L. In this embodiment, the core material 2 is formed in a plate shape extending along the extension direction L as shown in Figs. 1 to 3, and among the directions substantially perpendicular to the extension direction L, a direction substantially perpendicular to the plate surface constitutes the weak axis direction W, and a direction substantially parallel to the plate surface constitutes the strong axis direction S. Note that the shape of the core material 2 is not particularly limited as long as it extends at least along the extension direction L and has a weak axis direction W and a strong axis direction S that are substantially perpendicular to the extension direction L, and may have a shape other than a plate shape.

In this embodiment, as shown in Figures 2 and 3, the core material 2 is attached to the restraining material 3 so that both ends of the core material 2 in the extension direction L protrude from both sides of the restraining material 3 in the extension direction L. Each of the ends of the core material 2 in the extension direction L protruding from both sides of the restraining material 3 is directly or indirectly connected to two components (e.g., columns and beams) provided at a distance on a frame (not shown). However, as long as the core material 2 can be connected between two components along the extension direction L, it is not limited to this embodiment, and for example, it may be attached to the restraining material 3 so that it fits inside both ends of the extension direction L of the restraining material 3.

The core material 2 is attached to the restraining material 3 so that at least a portion of the core material 2 is allowed to move relative to the restraining material 3 at least along the extension direction L. By allowing the core material 2 to move relative to the restraining material 3 in the extension direction L, when the core material 2 receives a compressive stress of a predetermined amount or more in the extension direction L, it can plastically deform in the extension direction L while being buckled and restrained by the restraining material 3. In addition, when the core material 2 receives a tensile stress or compressive stress of a predetermined amount or less in the extension direction L, it can elastically deform in the extension direction L while being buckled and restrained by the restraining material 3. The method of attaching the core material 2 to the restraining material 3 is not particularly limited as long as at least a portion of the core material 2 is movable relative to the extension direction L. For example, when attaching the restraining material 3 to the core material 2, which will be described in detail below, the pressing force from the restraining material 3 to the core material 2 may be adjusted to allow the core material 2 to move relative to the restraining material 3.

In this embodiment, as shown in FIG. 1 and FIG. 4 to FIG. 6, a self-adhesive 5 is provided between the core material 2 and the weak axis restraint material 31 of the restraint material 3, which will be described later, at approximately the center of the extension direction L of the core material 2. In addition, an unbond material 6 is provided between the core material 2 and the weak axis restraint material 31 and the strong axis restraint material 32 of the restraint material 3, which will be described later, at both sides of the approximately center of the extension direction L of the core material 2, to reduce the frictional force generated between the core material 2 and the weak axis restraint material 31 and the strong axis restraint material 32. By providing the self-adhesive 5 at approximately the center of the extension direction L of the core material 2 in this way, the relative movement of the approximately center part of the core material 2 is suppressed, and the overall position of the core material 2 relative to the restraint material 3 (particularly the weak axis restraint material 31) is approximately fixed. The restraint material 3 can more reliably restrain the core material 2 from buckling by approximately fixing the overall position of the core material 2, which is the object of restraint. In addition, by providing the unbonded material 6 on both sides of the approximate center of the extension direction L of the core material 2, the core material 2 is allowed to move relative to the restraining material 3 (weak axis restraining material 31 and strong axis restraining material 32) on both sides of the approximate center of the extension direction L of the core material 2. By allowing the core material 2 to move relative to the restraining material 3, the above-mentioned plastic deformation and elastic deformation are possible. In addition, the friction force generated between the core material 2 and the restraining material 3 is reduced by the unbonded material 6, so that the restraining material 3 is prevented from receiving a force (axial force) in the extension direction L from the core material 2. As a result, the restraining material 3 can reduce the force received from the core material 2 by at least the amount of the axial force of the core material 2 that is suppressed, so that the strength for buckling restraint of the core material 2 can be secured. Therefore, the buckling restrained structural material 1 of this embodiment has excellent buckling restraint properties.

Here, the approximately central portion where the self-adhesive 5 is provided means a region of a predetermined length between both ends of the extension direction L of the core material 2. In this embodiment, as shown in FIG. 1, the approximately central portion is set in a region that extends a predetermined length along the extension direction L on both sides of the approximate center of the extension direction L of the core material 2. By arranging the approximately central portion with the approximate center of the extension direction L of the core material 2 as the center, the relative movement of the core material 2 on both sides of the extension direction L of the approximately central portion can be made symmetrical in the extension direction L, and the vibration energy generated in the frame can be absorbed symmetrically in the extension direction L. However, the approximately central portion is not limited to this embodiment as long as it is between both ends of the extension direction L of the core material 2, and may be set at a position shifted from the approximate center of the extension direction L of the core material 2.

The size of the portions where the self-adhesive 5 and the unbonding material 6 are provided can be set appropriately within a range that allows relative movement of the portions other than the approximately central portion of the core material 2 while suppressing relative movement of the approximately central portion of the core material 2, and can suppress the axial force that the restraining material 3 receives from the core material 2. For example, the length of the extension direction L of the approximately central portion where the self-adhesive 5 is provided is not particularly limited, but is preferably 1/13 to 1/5, more preferably 1/11 to 1/7, and even more preferably 1/10 to 1/8 of the entire length of the extension direction L of the narrow width portion 22 of the core material 2 described later. The length of the extension direction L of the portion where the unbonding material 6 is provided is not particularly limited, but can be a length corresponding to the portions on both sides of the approximately central region where the self-adhesive 5 is provided.

As shown in Figs. 1 and 5, the self-adhesive 5 is provided in the approximate center of the extension direction L of the core material 2, on both sides facing a pair of weak axis restraint members 31, 31 described below, over approximately the entire length of the width direction (strong axis direction S) of the core material 2. There are no particular limitations on the self-adhesive 5, so long as it is a material that can adhere the core material 2 and the restraint member 3 (particularly the weak axis restraint member 31) to each other and can suppress the relative movement of the core material 2 in the extension direction L with respect to the restraint member 3 (particularly the weak axis restraint member 31), and for example, an acrylic adhesive or butyl rubber can be used.

As shown in FIG. 1, the unbond material 6 includes a weak axis unbond material 61 provided on the side facing each of the pair of weak axis restraint materials 31, 31, and a strong axis unbond material 62 provided on the side facing each of the pair of strong axis restraint materials 32, 32 described later. The weak axis unbond material 61 is provided on both sides facing each of the pair of weak axis restraint materials 31, 31 at both sides of the approximately central portion of the extension direction L of the core material 2. The strong axis unbond material 62 is provided at a position corresponding to each of the pair of strong axis restraint materials 32, 32. The unbond material 6 is not particularly limited as long as it can reduce the friction force generated between the core material 2 and the restraint material 3 and can allow relative movement of the core material 2 in the extension direction L with respect to the restraint material 3, and can be, for example, Teflon (registered trademark), phenolic resin, ultra-high molecular weight polyethylene, etc.

The core material 2 extends along the extension direction L and has a weak axis direction W and a strong axis direction S, and its shape is not particularly limited. In this embodiment, as shown in FIG. 1 and FIG. 2, the core material 2 has wide portions 21, 21 provided at both ends of the extension direction L and a narrow portion 22 provided between the wide portions 21, 21 at both ends of the extension direction L. The wide portion 21 is wider (length in the strong axis direction S) than the narrow portion 22, and the narrow portion 22 is narrower (length in the strong axis direction S) than the wide portion 21. By forming the wide portion 21 at both ends of the extension direction L in this way, the strength of both ends is greater than that of the intermediate region in which the narrow portion 22 is formed, and it is possible to suppress the deformation of both ends of the core material 2 preferentially. In addition, by forming the narrow portion 22 in the intermediate region of the extension direction L, when the core material 2 is subjected to a tensile stress or compressive stress of a predetermined value or more in the extension direction L, the intermediate region of the core material 2 is preferentially deformed. The widths of the wide portion 21 and the narrow portion 22 are not particularly limited, as long as the width of the wide portion 21 is at least wider than the width of the narrow portion 22, and can be set appropriately according to the required strength. For example, the width of the wide portion 21 can be set to 3.0 to 4.0 times the width of the narrow portion 22. The lengths of the wide portion 21 and the narrow portion 22 in the extension direction L are also not particularly limited, and can be set appropriately according to the required strength. For example, the length of the wide portion 21 in the extension direction L can be set to 1/6 to 1/3 of the length of the narrow portion 22 in the extension direction L.

As shown in Figs. 1 to 3, the core material 2 may have ribs 23 extending in the weak axis direction W at both ends of the extension direction L. By providing ribs 23 extending in the weak axis direction W at both ends of the extension direction L of the core material 2, the bending rigidity in the weak axis direction W at both ends of the core material 2 is increased, and it is possible to suppress preferential deformation of both ends of the core material 2.

The core material 2 can be configured to, for example, yield preferentially over other members subjected to a predetermined or greater tensile or compressive stress in the extension direction L of the core material 2 when subjected to a predetermined or less tensile or compressive stress in the extension direction L of the core material 2, and to maintain its shape within the elastic deformation range when subjected to a predetermined or less tensile or compressive stress in the extension direction L of the core material 2. For this purpose, the core material 2 can be formed, for example, from a metal material, preferably from a steel material, and more preferably from a low-yield-point steel material. The low-yield-point steel material is a steel material that has a lower carbon content and a lower yield point than ordinary steel materials, and refers to, for example, a steel material with a strength of a yield point of 225 N/ ^mm2 or less and extremely high ductility. However, the core material 2 is not particularly limited as long as it is formed, for the above purpose, from a material that yields preferentially over other components of the buckling-constrained structural material 1 and components of the connected frame, and may be formed from ordinary steel material having a higher yield point than the low-yield-point steel material, or from aluminum or lead having a lower yield point than the low-yield-point steel material.

The restraining member 3 is a member that restrains (suppresses) the buckling of the core material 2 in a direction approximately perpendicular to the extension direction L. More specifically, the restraining member 3 restrains the buckling of the core material 2 in the weak axis direction W and the strong axis direction S that are approximately perpendicular to the extension direction L. By restraining the buckling of the core material 2 in the weak axis direction W and the strong axis direction S, the restraining member 3 enables stable plastic deformation of the core material 2 along the extension direction L when the core material 2 receives a tensile stress or compressive stress of a predetermined level or more in the extension direction L, and enables the core material 2 to absorb relatively large vibration energy. In addition, by restraining the buckling of the core material 2 in the weak axis direction W and the strong axis direction S, when the core material 2 receives a tensile stress or compressive stress of a predetermined level or less in the extension direction L, the restraining member 3 maintains the strength of the core material 2 in the extension direction L and helps the core material 2 resist external forces received from the frame.

As shown in Figures 1 to 3, the restraint material 3 comprises a pair of weak axis restraint materials 31, 31 provided on both sides of the weak axis direction W of the core material 2, and a pair of strong axis restraint materials 32, 32 provided on both sides of the strong axis direction S of the core material 2. The pair of weak axis restraint materials 31, 31 press and clamp the core material 2 in the weak axis direction W, and the pair of strong axis restraint materials 32, 32 press and clamp the core material 2 in the strong axis direction S. As a result, no gaps are formed between the weak axis restraint materials 31 on both sides of the weak axis direction W of the core material 2, and no gaps are formed between the strong axis restraint materials 32 on both sides of the strong axis direction S of the core material 2. In this way, no gap is formed between the core material 2 and the weak axis restraint member 31 and the strong axis restraint member 32, and the weak axis restraint member 31 and the strong axis restraint member 32 are directly or indirectly in contact with the core material 2, and the weak axis restraint member 31 and the strong axis restraint member 32 are attached to the core material 2, thereby reducing the force that protrudes from the core material 2 to the weak axis restraint member 31 and the strong axis restraint member 32 when an external force in the extension direction L is applied to the core material 2. Therefore, the force borne by the weak axis restraint member 31 and the strong axis restraint member 32 to restrain the buckling of the core material 2 is reduced, so that even a wooden restraint member with low strength can obtain excellent buckling restraint properties. In addition, for example, when the core material 2 is subjected to tensile stress in the extension direction L and the length of the core material 2 in the extension direction L increases, the lengths of the weak axis direction W and the strong axis direction S of the core material 2 are simultaneously shortened. Even in such a case, the weak axis restraint member 31 and the strong axis restraint member 32, which are in a state of pressing the core material 2 before the deformation of the core material 2, move or deform in accordance with the deformation of the core material 2, thereby maintaining direct or indirect contact between the core material 2 and the weak axis restraint member 31 and the strong axis restraint member 32. Therefore, even if the core material 2 is deformed by tensile stress in the extension direction L and the length of the core material 2 in the weak axis direction W and the strong axis direction S is shortened, the contact between the core material 2 and the weak axis restraint member 31 and the strong axis restraint member 32 is maintained, and an increase in the force of the core material 2 protruding is suppressed, and excellent buckling restraint properties can be obtained.

As described above, the weak axis restraint members 31 are provided on both sides of the core material 2 in the weak axis direction W, and are members that restrain the buckling of the core material 2 in the weak axis direction W. The weak axis restraint members 31 are fixed to the weak axis restraint members 31 arranged opposite to the opposite side of the weak axis direction W of the core material 2, thereby pressing and clamping the core material 2 in the weak axis direction W. In this embodiment, as shown in FIG. 4, the pair of weak axis restraint members 31, 31 are fixed to each other by a course thread screw B1 extending in the weak axis direction W so as to press and clamp the core material 2 in the weak axis direction W. The course thread screw B1 has a spiral screw groove on the outer periphery, and penetrates one weak axis restraint member 31 (screw hole 31c described later) and is screwed into the other weak axis restraint member 31, drawing the pair of weak axis restraint members 31, 31 in a direction toward each other. The coarse thread screw B1 has a larger mutual attraction force between the pair of weak axis restraint members 31, 31 than a combination of bolts and nuts, and the fastening force to the weak axis restraint member 31 is less likely to deteriorate over time. Therefore, by fixing the pair of weak axis restraint members 31, 31 to each other using the coarse thread screw B1, a high pressing force against the core material 2 can be obtained and the pressing force can be maintained for a long period of time. In addition, by using the coarse thread screw B1 to fix the pair of weak axis restraint members 31, 31, the number of holes (necessary when using a bolt) that are pre-formed in the weak axis restraint member 31 can be reduced, so that the strength of the weak axis restraint member 31 can be maintained high. As the coarse thread screw B1, it is preferable to use a partial thread screw (half screw) in which a thread groove is not provided from the intermediate position (for example, a position of approximately half the length) between the head having a tool hole and the tip to the vicinity of the head, and a thread groove is provided from the intermediate position to the tip. By maintaining the strength of the weak axis restraint member 31 high, excellent buckling restraint properties can be obtained. In addition, the pair of weak axis restraint members 31, 31 are not limited to this embodiment and may be fixed to each other using other known fixing means as long as they can be fixed to each other so as to press and clamp the core material 2 in the weak axis direction W.

The weak axis restraint member 31 is provided at least on both sides of the weak axis direction W of the core material 2, and the arrangement is not particularly limited as long as it can restrain the buckling of the core material 2 in the weak axis direction W. In this embodiment, the pair of weak axis restraint members 31, 31 are provided on both sides of the weak axis direction W of both the core material 2 and the pair of strong axis restraint members 32, 32, as shown in Figures 1 to 3. In other words, both the core material 2 and the pair of strong axis restraint members 32, 32 are provided between the pair of weak axis restraint members 31, 31. At this time, the strong axis restraint member 32 provided together with the core material 2 between the pair of weak axis restraint members 31, 31 is preferably formed to a size such that the thickness (length in the weak axis direction W) of the strong axis restraint member 32 is shorter than the thickness (length in the weak axis direction W) of the core material 2 before being provided, as shown in Figures 5 and 7. As a result, when the core material 2 and the pair of strong axis restraint members 32, 32 are sandwiched by the pair of weak axis restraint members 31, 31 in the weak axis direction W, no gap is generated between the pair of weak axis restraint members 31, 31 and the core material 2, but a gap G1 is generated between the pair of weak axis restraint members 31, 31 and the pair of strong axis restraint members 32, 32. The generation of this gap G1 suppresses the pair of strong axis restraint members 32, 32 from hindering the movement of the pair of weak axis restraint members 31, 31 toward each other when the pair of weak axis restraint members 31, 31 are fixed to each other so as to approach each other in the weak axis direction W in order to press and hold the core material 2 in the weak axis direction W. Therefore, the pressing force of the pair of weak axis restraint members 31, 31 on the core material 2 can be increased. Furthermore, as described below, when the strong axis restraint material 32 is compressed in the strong axis direction S, the strong axis restraint material 32 may expand in the weak axis direction W, but the gap G1 between the strong axis restraint material 32 and the weak axis restraint material 31 allows the strong axis restraint material 32 to expand in the weak axis direction W, promoting compression in the strong axis direction S. The gap G1 may disappear due to deformation of the pair of weak axis restraint materials 31, 31 when the pair of weak axis restraint materials 31, 31 are fixed to each other. Alternatively, the gap G1 may disappear due to deformation of the pair of strong axis restraint materials 32, 32 when the pair of side plates 4, 4 are fixed to the pair of weak axis restraint materials 31, 31 as described below. The size of the gap G1 (length in the weak axis direction W) is not particularly limited, but can be set to be, for example, 80% or more and less than 100% of the thickness (length in the weak axis direction W) of the core material 2.

The weak axis restraint member 31 is provided on both sides of the weak axis direction W of the core material 2, and may restrain the buckling of the core material 2 in the weak axis direction W, and its shape is not particularly limited. In this embodiment, as shown in Figures 1 to 3, the weak axis restraint member 31 is formed into a substantially rectangular shape in which a cross section perpendicular to the extension direction L is formed by a side extending in the weak axis direction W and a side extending in the strong axis direction S, and the cross-sectional area is substantially constant along the extension direction L. As can be clearly seen in Figures 2 and 3, the length of the extension direction L of the weak axis restraint member 31 is longer than the length of the extension direction L of the narrow width portion 22 of the core material 2, and shorter than the length of the entire extension direction L of the core material 2. As a result, a portion of the free end side of the wide portion 21 of the core material 2 in the extension direction L protrudes from the end of the pair of weak axis restraint members 31, 31 in the extension direction L, and a portion of the narrow portion 22 side of the wide portion 21 of the core material 2 in the extension direction L and the entirety of the narrow portion 22 in the extension direction L are sandwiched between the pair of weak axis restraint members 31, 31. Also, as can be clearly seen in FIG. 2, the length of the strong axis direction S of the weak axis restraint member 31 is approximately constant over the entire length of the extension direction L, is longer than the length of the strong axis direction S of the narrow portion 22 of the core material 2, and corresponds to the length of the strong axis direction S of the wide portion 21 of the core material 2. As a result, the entirety of the strong axis direction S of the portion of the narrow portion 22 side of the wide portion 21 of the core material 2 in the extension direction L and the entirety of the strong axis direction S of the narrow portion 22 are sandwiched between the pair of weak axis restraint members 31, 31.

As shown in FIG. 1, the surface of the weak axis restraint material 31 facing the core material 2 is formed substantially flat, and the weak axis restraint material 31 comes into direct or indirect surface contact with the plate surface of the core material 2 formed in a plate shape. The surface of the weak axis restraint material 31 facing the core material 2 has rib recesses 31a, 31a at both ends in the extension direction L that can accommodate the ribs 23 of the core material 2. As shown in FIG. 2 and FIG. 6, the rib recesses 31a are formed to a size that forms a gap G2 between the peripheral wall surrounding the rib recesses 31a and the rib 23 when the core material 2 is attached to the weak axis restraint material 31. This prevents the rib 23 from abutting against the peripheral wall of the rib recesses 31a, and prevents the rib 23 from hindering the relative movement of the core material 2 with respect to the weak axis restraint material 31.

As shown in FIG. 1, the weak axis restraint member 31 has a side plate recess 31b for fixing the side plate 4 described later on both sides in the strong axis direction S. The side plate recess 31b is formed to a depth corresponding to the thickness of the side plate 4 (length in the strong axis direction S). As a result, when the side plate 4 is fixed to the side plate recess 31b, the side surface of the weak axis restraint member 31 other than the side plate recess 31b and the surface of the side plate 4 are approximately flush. In addition, the length of the extension direction L of the side plate recess 31b corresponds to the width (length in the extension direction L) of the side plate 4. As a result, when the side plate 4 is fixed to the side plate recess 31b, the relative movement of the side plate 4 in the extension direction L with respect to the weak axis restraint member 31 is suppressed. In addition, the side plate recess 31b extends over the entire length of the weak axis direction W of the weak axis restraint member 31. This allows the side plate 4 to be fixed so as to straddle both of the side plate recesses 31, 31b of the pair of weak axis restraint members 31, 31 (see FIG. 3). The side plate recesses 31b are provided at intervals along the extension direction L according to the number of side plates 4 to be provided. However, for example, when the side plate is formed as a single member extending in the extension direction L of the weak axis restraint member 31, only one side plate recess may be provided to correspond to that side plate. Also, the side plate recess 31b does not necessarily have to be provided, and the side plate 4 may be fixed to a substantially flat side surface of the weak axis restraint member 31. In that case, a complementary member may be fixed to a portion other than the portion to which the side plate 4 is fixed so that the side surface of the weak axis restraint member 31 to which the side plate 4 is fixed is substantially flat.

As shown in FIG. 1, the weak axis restraint material 31 is provided with a screw hole 31c through which the course thread screw B1 can pass. The screw hole 31c is provided near one end and the other end of the weak axis restraint material 31 in the strong axis direction S at a position in the extension direction L corresponding to the narrow width portion 22 of the core material 2, where the screw hole 31c does not overlap with the narrow width portion 22 of the core material 2 in the weak axis direction W. By providing the screw hole 31c at a position corresponding to the outside of the strong axis direction S of the narrow width portion 22 of the core material 2, when fixing the pair of weak axis restraint materials 31, 31 with the course thread screw B1, the course thread screw B1 can be provided at a distance from the core material 2 without penetrating the core material 2. The screw holes 31c are provided at intervals in the extension direction L so that they alternate between one and the other of the pair of weak axis restraint materials 31, 31 in the extension direction L. As a result, as shown in Figures 2 and 3, the fixing directions of adjacent course thread screws B1 in the extension direction L and the strong axis direction S can be reversed, allowing the pair of weak axis restraint members 31, 31 to be fixed in a balanced manner.

The weak axis restraint material 31 is made of wood. There are no particular limitations on the wood used, so long as the weak axis restraint material 31 can be formed to have the strength to restrain buckling in the weak axis direction W of the core material 2. In this embodiment, the weak axis restraint material 31 is made of laminated veneer lumber (LVL) in which multiple plate materials are stacked in the strong axis direction S, as shown in FIG. 1. Note that in other figures, the stacking of plate materials is omitted for ease of viewing. As for wood, other than LVL, for example, laminated lumber, cross-laminated timber (CLT), solid wood, etc. can be used.

The strong axis restraint members 32 are provided on both sides of the core material 2 in the strong axis direction S, and are members that restrain the buckling of the core material 2 in the strong axis direction S. The strong axis restraint members 32 are attached to the core material 2 so as to press and clamp the core material 2 in the strong axis direction S. The method of attaching the strong axis restraint members 32 to the core material 2 is not particularly limited as long as the strong axis restraint members 32 can be attached to the core material 2 so as to press and clamp the core material 2 in the strong axis direction S. In this embodiment, the pair of strong axis restraint members 32, 32 are attached to the core material 2 by a pair of side plates 4, 4 (side plates 41, 41 for the strong axis restraint member described later) fixed to the side surfaces on both sides of the weak axis restraint member 31 in the strong axis direction S, as shown in Figure 1 to Figure 3. The pair of side plates 4, 4 (side plates 41, 41 for the strong axis restraint member) are fixed to the pair of weak axis restraint members 31, 31 so as to compress the pair of strong axis restraint members 32, 32 in the strong axis direction S between the core material 2 and the strong axis restraint members 32, 32, as shown in Figure 4. A pair of strong axis restraint materials 32, 32 compressed in the strong axis direction S clamp the core material 2 by pressing it with a repulsive force against the compression.

The strong axis restraint members 32 are provided on both sides of the core material 2 in the strong axis direction S, and the shape is not particularly limited as long as the strong axis restraint members 32 can restrain buckling of the core material 2 in the strong axis direction S. In this embodiment, the strong axis restraint members 32 are formed in a substantially rectangular flat plate shape formed by a side extending in the extension direction L and a side extending in the strong axis direction S, as shown in FIG. 1. The pair of strong axis restraint members 32, 32 are formed to a size such that the sum of the lengths in the strong axis direction S of the core material 2 and the pair of strong axis restraint members 32, 32 is longer than the length of the strong axis direction S of the weak axis restraint member 31, 31 before the pair of side plates 4, 4 (side plates 41, 41 for the strong axis restraint members) are fixed to the pair of weak axis restraint members 31, 31, as shown in FIG. 7. Therefore, the pair of strong axis restraint members 32, 32 protrude outward in the strong axis direction S from the side surface (bottom surface of the side plate recess 31b) of the pair of weak axis restraint members 31, 31 in the strong axis direction S when the pair of side plates 4, 4 (side plates 41, 41 for the strong axis restraint member) is not fixed to the pair of weak axis restraint members 31, 31. By fixing the pair of side plates 4, 4 (side plates 41, 41 for the strong axis restraint member) to the pair of weak axis restraint members 31, 31 from the state in which the pair of strong axis restraint members 32, 32 protrude from the side surfaces of the pair of weak axis restraint members 31, 31 (the state in FIG. 7), the pair of strong axis restraint members 32, 32 are pressed between the core material 2 and the pair of side plates 4, 4 and compressed in the strong axis direction S. The compressed pair of strong axis restraint members 32, 32 sandwich the core material 2 so as to press it by a repulsive force against compression. The protruding portions of the pair of strong axis restraint members 32, 32 may disappear due to deformation of the pair of strong axis restraint members 32, 32 when the pair of side plates 4, 4 are fixed to the pair of weak axis restraint members 31, 31. The size of the protruding portions of the pair of strong axis restraint members 32, 32 (length in the strong axis direction S) is not particularly limited, but can be set to a size (shorter length) smaller than the depth (length in the strong axis direction S) of the side plate recess 31b, for example, and can be set so that the sum of the lengths of the core material 2 and the pair of strong axis restraint members 32, 32 in the strong axis direction S exceeds 100% and is equal to or smaller than 105% of the length of the weak axis restraint member 31 in the strong axis direction S.

In this embodiment, as shown in Figures 1 and 2, a pair of strong axis restraint members 32, 32 are provided at intervals over substantially the entire length of the extension direction L of the narrow width portion 22 of the core material 2 (11 in the illustrated example). By arranging the multiple strong axis restraint members 32 at intervals from each other along the extension direction L, a fixing means (course thread screw B1) for fixing the pair of weak axis restraint members 31, 31 to each other can be provided in a place where the strong axis restraint member 32 is not provided without processing the strong axis restraint member 32 (for example, without providing a through hole) (see Figures 2 and 4). In addition, in a place where the strong axis restraint member 32 is not provided, the movement of the pair of weak axis restraint members 31, 31 toward each other is not restricted, so that the pair of weak axis restraint members 31, 31 can be moved in a direction toward each other without being restricted by the strong axis restraint member 32, and sufficient pressing force can be applied to the core material 2. The number of strong axis restraint members 32 is not particularly limited, but from the viewpoint of reducing the frictional force generated between the core material 2 by reducing the size of each strong axis restraint member 32 and increasing the number of strong axis restraint members 32 to increase the number of spaces between the strong axis restraint members 32, three or more are preferable, six or more are more preferable, and nine or more are even more preferable. As a result, the strong axis restraint member 32 is prevented from receiving an axial force in the extension direction L from the core material 2, so that the buckling restrained structural material 1 can obtain a better buckling restraint property. In addition, from the viewpoint of ease of installation of the strong axis restraint member 32, the number of strong axis restraint members 32 is preferably 19 or less, more preferably 16 or less, and even more preferably 13 or less. However, as long as each of the pair of strong axis restraint members 32, 32 is provided on both sides of the strong axis direction S of the core material 2, it is not limited to the above example, and it may be provided as one member so as to extend over approximately the entire length of the extension direction L of the narrow width portion 22.

The strong axis restraint member 32 is made of wood. There are no particular limitations on the wood used, so long as the strong axis restraint member 32 can be formed to have the strength to restrain buckling in the strong axis direction S of the core material 2. There are no particular limitations on the wood that constitutes the strong axis restraint member 32, and examples that can be used include solid wood, laminated timber, LVL, and CLT.

As described above, the buckling restraint structural member 1 may include a pair of side plates 4, 4 fixed to both side surfaces of the weak axis restraint member 31 in the strong axis direction S, as shown in Figures 1 and 2. The side plate 4 is a member fixed so as to straddle both of the pair of weak axis restraint members 31, 31 on both side surfaces of the weak axis restraint member 31 in the strong axis direction S. In this embodiment, the side plate 4 includes a strong axis restraint member side plate 41 for attaching the strong axis restraint member 32 to the core material 2 so as to press against the core material 2, and a weak axis restraint member side plate 42 for fixing the ends of the pair of weak axis restraint members 31, 31 in the extension direction L to each other.

As shown in Figures 1 to 3 and 5, the side plate 41 for the strong axis restraint material is fixed to the side surfaces on both sides of the pair of weak axis restraint materials 31, 31 in the strong axis direction S so that the pair of strong axis restraint materials 32, 32 press and clamp the core material 2 in the strong axis direction S. In this embodiment, the side plate 41 for the strong axis restraint material is formed in a flat plate shape and is fixed to the side surfaces of the pair of weak axis restraint materials 31, 31 in the strong axis direction S arranged approximately flush with each other (see Figure 5). Here, as described above, the pair of strong axis restraint materials 32, 32 protrude from the side surfaces of the pair of weak axis restraint materials 31, 31 before the side plate 41 for the strong axis restraint material is fixed to the side surfaces of the pair of weak axis restraint materials 31, 31 (see Figure 7). When the pair of strong axis restraint member side plates 41, 41 are fixed to the side surfaces of the pair of weak axis restraint members 31, 31, they press the pair of strong axis restraint members 32, 32 toward the core material 2 so that the ends of the pair of strong axis restraint members 32, 32 are approximately flush with the side surfaces of the pair of weak axis restraint members 31, 31. As a result, the core material 2 is pressed and sandwiched by the pair of strong axis restraint members 32, 32 from both sides in the strong axis direction S. However, the strong axis restraint member side plates only need to be configured to press the strong axis restraint members toward the core material, and may be formed, for example, not flat, but with a portion protruding toward the strong axis restraint member, and may be configured so that the protruding portion presses the strong axis restraint member when fixed to the weak axis restraint member.

The strong axis restraint member side plate 41 can be fixed to the weak axis restraint member 31 by a fixing screw B2, as shown in Figs. 2, 3 and 5, though it is not particularly limited thereto. The fixing screw B2 has a helical screw groove on the outer periphery, and is screwed into the weak axis restraint member 31 through a screw hole 41a provided in the strong axis restraint member side plate 41, thereby fixing the strong axis restraint member side plate 41 to the weak axis restraint member 31. By using the fixing screw B2 to fix the strong axis restraint member side plate 41 to the weak axis restraint member 31, it is not necessary to provide a hole in the weak axis restraint member 31 in advance, so that the strength of the weak axis restraint member 31 can be maintained high. The buckling restraint structural member 1 can obtain excellent buckling restraint properties by maintaining the strength of the weak axis restraint member 31 high. The fixing screw B2 is not particularly limited, and a known screw such as a tapping screw can be used.

In this embodiment, as shown in Figures 3 and 5, the side plate 41 for the strong axis restraint material is fixed to one of the weak axis restraint materials 31 with one fixing screw B2, and is fixed to the other weak axis restraint material 31 with one fixing screw B2. Note that the side plate 41 for the strong axis restraint material is not limited to this embodiment, and may be fixed using other known fixing means, as long as it is fixed to the weak axis restraint material 31 so as to press and clamp the strong axis restraint material 32 in the strong axis direction S.

The material of the side plate 41 for the strong axis restraint member is not particularly limited, so long as it has the strength to attach the pair of strong axis restraint members 32, 32 to the core material 2 so that the pair of strong axis restraint members 32, 32 press and clamp the core material 2 in the strong axis direction S. The side plate 41 for the strong axis restraint member can be made of wood, for example. The wood used is not particularly limited, and examples include solid wood, laminated wood, LVL, and CLT.

As shown in Figs. 1 to 3 and 6, the side plate 42 for the weak axis restraint material is fixed to both sides of the end of the pair of weak axis restraint materials 31, 31 in the strong axis direction S so that the ends of the pair of weak axis restraint materials 31, 31 in the extension direction L sandwich the wide portion 21 of the core material 2 in the weak axis direction W. In this embodiment, the side plate 42 for the weak axis restraint material is formed in a flat plate shape and is fixed to the side surface of the pair of weak axis restraint materials 31, 31 in the strong axis direction S arranged approximately flush with each other (see Fig. 6). The side plate 42 for the weak axis restraint material can be fixed to the weak axis restraint material 31 by a fixing screw B2, although it is not particularly limited. The fixing screw B2 has a spiral screw groove on the outer periphery, and is screwed into the weak axis restraint material 31 through a screw hole 42a provided in the side plate 42 for the weak axis restraint material, thereby fixing the side plate 42 for the weak axis restraint material to the weak axis restraint material 31. By using the fixing screw B2 to fix the side plate 42 for the weak axis restraint member to the weak axis restraint member 31, there is no need to pre-drill holes in the weak axis restraint member 31, so the strength of the weak axis restraint member 31 can be maintained high. The buckling restraint structural member 1 can obtain excellent buckling restraint properties by maintaining the strength of the weak axis restraint member 31 high.

Here, as described above, the width (length in the strong axis direction S) of the weak axis restraint material 31 corresponds to the width (length in the strong axis direction S) of the wide portion 21 of the core material 2. Therefore, at both ends of the extension direction L of the pair of weak axis restraint materials 31, 31, it is not possible to provide a course thread screw B1 for fixing the weak axis restraint materials 31, 31 to each other. If the ends of the weak axis restraint materials 31, 31 are not sufficiently fixed, the core material 2 is likely to buckle locally at the ends. In this embodiment, as shown in FIG. 6, the pair of weak axis restraint materials 31, 31 are fixed to each other at a position corresponding to the wide portion 21 of the core material 2 by fixing a pair of side plates 4, 4 (side plates 42, 42 for the weak axis restraint material) to the side surfaces on both sides of the pair of weak axis restraint materials 31, 31 in the strong axis direction S with a fixing screw B2 (optionally in combination with adhesive A). In particular, the side plate 42 for the weak axis restraint member is fixed with a larger number of fixing screws B2 (two for one weak axis restraint member 31 and two for the other weak axis restraint member 31) than the side plate 41 for the strong axis restraint member provided at a position corresponding to the narrow width portion 22 of the core material 2 (optionally using adhesive A in combination). This allows the pair of weak axis restraint members 31, 31 to be firmly fixed to each other at a position corresponding to the wide width portion 21 of the core material 2. By fixing the pair of weak axis restraint members 31, 31 to each other only by fixing the pair of side plates 4, 4 with the fixing screws B2 (optionally using adhesive A in combination), it is not necessary to increase the width (length in the strong axis direction S) of the weak axis restraint member 31 at a position corresponding to the wide width portion 21 of the core material 2 to secure a position for providing the course thread screw B1, so the buckling restraint structural material 1 can be made smaller. The adhesive A that is optionally used in combination is not particularly limited, and a known adhesive such as epoxy resin can be used.

There are no particular limitations on the material that the weak axis restraint side plate 42 is made of, so long as it has the strength to attach the pair of weak axis restraint members 31, 31 to the core material 2 so that the pair of weak axis restraint members 31, 31 sandwich the core material 2 in the weak axis direction W. The weak axis restraint side plate 42 can be made of wood, for example. There are no particular limitations on the wood that can be used, and examples include solid wood, laminated timber, LVL, and CLT.

Next, a method for manufacturing the buckling restrained structural material 1 of this embodiment will be described. Below, several steps performed in the manufacturing method will be described, but not all steps necessarily need to be performed, and the order of the steps performed is not limited to the order described below. Furthermore, the steps shown below are an example, and the method for manufacturing the buckling restrained structural material 1 of this embodiment is not limited to the example below.

As shown in Figures 1 to 3, the manufacturing method of the buckling restrained structural material 1 includes a step of providing a pair of weak axis restraint members 31, 31 on both sides of the weak axis direction W of the core material 2 so as to press and clamp the core material 2 in the weak axis direction W, and a step of providing a pair of strong axis restraint members 32, 32 on both sides of the strong axis direction S of the core material 2 so as to press and clamp the core material 2 in the strong axis direction S. In the buckling restrained structural material 1 manufactured by these steps, as described above, no gaps are formed between the core material 2 and the weak axis restraint members 31 and the strong axis restraint members 32, and the core material 2 is in direct or indirect contact with the weak axis restraint members 31 and the strong axis restraint members 32, and the force that protrudes from the core material 2 to the weak axis restraint members 31 and the strong axis restraint members 32 when an external force in the extension direction L is applied to the core material 2 is reduced. Therefore, the force borne by the weak axis restraint member 31 and the strong axis restraint member 32 to restrain the buckling of the core material 2 is reduced, so that excellent buckling restraint can be obtained even with a low-strength wooden restraint member.

As shown in Figures 1 and 4 to 6, the manufacturing method of the buckling restrained structural material 1 may include a step of providing a self-adhesive 5 between the core material 2 and the weak axis restraint material 31 of the restraint material 3 at approximately the center of the extension direction L of the core material 2, which adheres the core material 2 and the weak axis restraint material 31 of the restraint material 3 to each other, and a step of providing an unbond material 6 between the core material 2 and the weak axis restraint material 31 and the strong axis restraint material 32 at both sides of the approximately center of the extension direction L of the core material 2, which reduces the frictional force generated between the core material 2 and the weak axis restraint material 31 and the strong axis restraint material 32 of the restraint material 3. By providing the self-adhesive 5 at approximately the center of the extension direction L of the core material 2 in this way, the relative movement of the approximately center of the core material 2 is suppressed, and the overall position of the core material 2 relative to the restraint material 3 (particularly the weak axis restraint material 31) is approximately fixed. In addition, by providing the unbond material 6 on both sides of the approximate center of the extension direction L of the core material 2, the core material 2 can move relative to the restraining material 3 on both sides of the approximate center of the extension direction L of the core material 2. However, for example, when providing the weak axis restraining material 31 and the strong axis restraining material 32, the pressing force from the weak axis restraining material 31 and the strong axis restraining material 32 to the core material 2 can be adjusted to suppress the relative movement of a part of the core material 2 and allow the relative movement of the other part of the core material 2 without providing the self-adhesive 5 and the unbond material 6.

The process of providing the pair of weak axis restraint members 31, 31 may include a process of fixing the pair of weak axis restraint members 31, 31 to each other with a course thread screw B1 extending in the weak axis direction W so as to press and clamp the core material 2 in the weak axis direction W, as shown in Figures 3 and 4. In this process, the course thread screw B1 is screwed into the other weak axis restraint member 31 through the screw hole 31c of one weak axis restraint member 31. By fixing the pair of weak axis restraint members 31, 31 to each other using the course thread screw B1, as described above, it is possible to obtain a high pressing force against the core material 2 and to maintain the pressing force for a long period of time. However, the pair of weak axis restraint members 31, 31 may be fixed to each other using other known fixing means.

The step of providing the pair of weak axis restraint members 31, 31 may include a step of providing the pair of weak axis restraint members 31, 31 on both sides of the weak axis direction W of both the core material 2 and the pair of strong axis restraint members 32, 32, as shown in Figures 2 and 5. In this case, it is preferable that the strong axis restraint member 32 is formed to a size such that the length of the weak axis direction W of the strong axis restraint member 32 is shorter than the length of the weak axis direction W of the core material 2 before being provided. As a result, as described above, when the pair of weak axis restraint members 31, 31 are fixed to each other, the pair of strong axis restraint members 32, 32 are prevented from hindering the movement of the pair of weak axis restraint members 31, 31 toward each other, so that the pressing force of the pair of weak axis restraint members 31, 31 on the core material 2 can be increased.

The step of providing the pair of strong axis restraint members 32, 32 may include a step of fixing a pair of side plates 4, 4 (side plates 41, 41 for the strong axis restraint members) to both sides of the weak axis restraint member 31 in the strong axis direction S so that the pair of strong axis restraint members 32, 32 are compressed in the strong axis direction S between the core material 2, as shown in FIG. 5. The pair of strong axis restraint members 32, 32 compressed in the strong axis direction S clamp the core material 2 so as to press it by the repulsive force against the compression. In order to provide the pair of strong axis restraint members 32, 32 so as to be compressed in the strong axis direction S, for example, the pair of strong axis restraint members 32, 32 are formed to a size such that the sum of the lengths in the strong axis direction S of the core material 2 and the pair of strong axis restraint members 32, 32 is longer than the length in the strong axis direction S of the weak axis restraint member 31, as shown in FIG. 7, before the pair of side plates 4, 4 (side plates 41, 41 for the strong axis restraint members) are fixed to the pair of weak axis restraint members 31, 31. In this case, the pair of strong axis restraint members 32, 32 protrude outward in the strong axis direction S from the side surface (bottom surface of the side plate recess 31b) of the pair of weak axis restraint members 31, 31 in the strong axis direction S when the pair of side plates 4, 4 (side plates 41, 41 for the strong axis restraint members) are not fixed to the pair of weak axis restraint members 31, 31. By fixing the pair of side plates 4, 4 (side plates 41, 41 for the strong axis restraint members) to the pair of weak axis restraint members 31, 31 (state of FIG. 5) from the state in which the pair of strong axis restraint members 32, 32 protrude from the side surfaces of the pair of weak axis restraint members 31, 31 (state of FIG. 7), the pair of strong axis restraint members 32, 32 are pressed between the core material 2 and the pair of side plates 4, 4 and compressed in the strong axis direction S.

In this embodiment, as described above, as shown in FIG. 1 and FIG. 2, the core material 2 has wide portions 21, 21 provided at both ends in the extension direction L, and narrow portions 22 provided between the wide portions 21, 21 at both ends in the extension direction L. The width of the weak axis restraint material 31 (length in the strong axis direction S) corresponds to the width of the wide portion 21 of the core material 2 (length in the strong axis direction S). Therefore, at both ends in the extension direction L of the pair of weak axis restraint materials 31, 31, it is not possible to provide a course thread screw B1 for fixing the weak axis restraint materials 31, 31 to each other. If the ends of the weak axis restraint materials 31, 31 are not sufficiently fixed, the core material 2 is more likely to buckle locally at the ends. Therefore, as shown in FIG. 6, the step of providing the pair of weak axis restraint members 31, 31 may include a step of fixing the pair of weak axis restraint members 31, 31 to each other by fixing a pair of side plates 4, 4 (side plates 42, 42 for the weak axis restraint members) to both side surfaces of the pair of weak axis restraint members 31, 31 in the strong axis direction S at a position corresponding to the wide portion 21 of the core material 2 with a fixing screw B2 (optionally in combination with adhesive A). This makes it possible to more firmly restrain the buckling of the wide portion 21 of the core material 2.

The step of providing a pair of strong axis restraint members 32, 32 may include a step of providing a pair of strong axis restraint members 32, 32 over substantially the entire length of the narrow width portion 22 in the extension direction L, as shown in Figures 1 and 2. In the illustrated example, a pair of strong axis restraint members 32, 32 are provided at intervals over substantially the entire length of the narrow width portion 22 in the extension direction L of the core material 2 (11 in the illustrated example). By arranging the multiple strong axis restraint members 32 at intervals from each other along the extension direction L, as described above, it is possible to apply sufficient pressing force from the pair of weak axis restraint members 31, 31 to the core material 2. However, each of the pair of strong axis restraint members 32, 32 may be provided as a single member so as to extend over substantially the entire length of the narrow width portion 22 in the extension direction L.

LIST OF SYMBOLS 1 buckling restraint structural material 2 core material 21 wide portion 22 narrow portion 23 rib 3 restraint material 31 weak axis restraint material 31a rib recess 31b side plate recess 31c screw hole 32 strong axis restraint material 4 side plate 41 side plate for strong axis restraint material 41a screw hole 42 side plate for weak axis restraint material 42a screw hole 5 self-adhesive 6 unbond material 61 weak axis unbond material 62 strong axis unbond material A adhesive B1 coarse thread screw B2 fixing screw G1, G2 gap L extension direction S strong axis direction W weak axis direction

Claims (10)

A core material extending along an extension direction and having a weak axis direction and a strong axis direction substantially perpendicular to the extension direction;
A buckling-constrained structural material comprising a wooden restraining member for restraining buckling of the core material in the weak axis direction and the strong axis direction,
The restraining material is
a pair of weak axis restraint members provided on both sides of the core material in the weak axis direction so as to press and sandwich the core material in the weak axis direction;
a pair of strong axis restraint members provided on both sides of the core material in the strong axis direction so as to press and hold the core material in the strong axis direction ;
the pair of weak axis restraint members are provided on both sides in the weak axis direction of both the core material and the pair of strong axis restraint members,
The strong axis restraint material is formed to a size such that the length of the strong axis restraint material in the weak axis direction is shorter than the length of the core material in the weak axis direction .
Buckling-restrained structural materials. The pair of weak axis restraint members are fixed to each other by coarse thread screws extending in the weak axis direction so as to press and sandwich the core material in the weak axis direction.
The buckling restrained structural material of claim 1. The buckling restraint structural member includes a pair of side plates fixed to both side surfaces of the weak axis restraint member in the strong axis direction,
The pair of side plates are fixed to the pair of weak axis restraint members so as to compress the pair of strong axis restraint members in the strong axis direction between the pair of side plates and the core material.
A buckling restrained structural material according to claim 1 or 2 . the pair of weak axis restraint members are disposed on both sides of the core member and the pair of strong axis restraint members in the weak axis direction,
The pair of strong axis restraint members are formed to a size such that a sum of the lengths of the core material and the pair of strong axis restraint members in the strong axis direction is longer than a length of the weak axis restraint member in the strong axis direction before the pair of side plates are fixed to the pair of weak axis restraint members.
The buckling restrained structural material according to claim 3 . Between the core material and the weak axis restraint material, a self-adhesive is provided in an approximately central portion of the core material in the extension direction, which adheres the core material and the weak axis restraint material to each other, and between the core material and the weak axis restraint material and the strong axis restraint material, an unbond material is provided in both sides of the approximately central portion of the core material in the extension direction, which reduces frictional forces generated between the core material and the weak axis restraint material and the strong axis restraint material.
The buckling restrained structural material according to any one of claims 1 to 4 . The core material includes a wide portion provided at both end sides in the extension direction and a narrow portion provided between the wide portions at both end sides in the extension direction,
The pair of weak axis restraint members are fixed to each other by fixing a pair of side plates to both side surfaces of the pair of weak axis restraint members in the strong axis direction at positions corresponding to the wide portion of the core material with fixing screws.
A buckling-restrained structural material according to any one of claims 1 to 5 . The core material includes a wide portion provided at both end sides in the extension direction and a narrow portion provided between the wide portions at both end sides in the extension direction,
The pair of strong axis restraint members are provided over substantially the entire length of the narrow width portion in the extending direction.
The buckling restrained structural material according to any one of claims 1 to 6 . A core material extending along an extension direction and having a weak axis direction and a strong axis direction substantially perpendicular to the extension direction;
a wooden restraining member for restraining buckling of the core member in the weak axis direction and the strong axis direction;
A buckling restraint structural member comprising:
The restraining material is
a pair of weak axis restraint members provided on both sides of the core material in the weak axis direction so as to press and sandwich the core material in the weak axis direction;
a pair of strong axis restraining members provided on both sides of the core material in the strong axis direction so as to press and hold the core material in the strong axis direction;
Equipped with
The buckling restraint structural member includes a pair of side plates fixed to both side surfaces of the weak axis restraint member in the strong axis direction,
The pair of side plates are fixed to the pair of weak axis restraint members so as to compress the pair of strong axis restraint members in the strong axis direction between the pair of side plates and the core material.
Buckling-restrained structural material. A core material extending along an extension direction and having a weak axis direction and a strong axis direction substantially perpendicular to the extension direction;
a wooden restraining member for restraining buckling of the core member in the weak axis direction and the strong axis direction;
A buckling restraint structural member comprising:
The restraining material is
a pair of weak axis restraint members provided on both sides of the core material in the weak axis direction so as to press and sandwich the core material in the weak axis direction;
a pair of strong axis restraining members provided on both sides of the core material in the strong axis direction so as to press and hold the core material in the strong axis direction;
Equipped with
The core material includes a wide portion provided at both end sides in the extension direction and a narrow portion provided between the wide portions at both end sides in the extension direction,
The pair of weak axis restraint members are fixed to each other by fixing a pair of side plates to both side surfaces of the pair of weak axis restraint members in the strong axis direction at positions corresponding to the wide portion of the core material with fixing screws.
Buckling-restrained structural materials. A core material extending along an extension direction and having a weak axis direction and a strong axis direction substantially perpendicular to the extension direction;
a wooden restraining member for restraining buckling of the core member in the weak axis direction and the strong axis direction;
A buckling restraint structural member comprising:
The restraining material is
a pair of weak axis restraint members provided on both sides of the core material in the weak axis direction so as to press and sandwich the core material in the weak axis direction;
a pair of strong axis restraining members provided on both sides of the core material in the strong axis direction so as to press and hold the core material in the strong axis direction;
Equipped with
The core material includes a wide portion provided at both end sides in the extension direction and a narrow portion provided between the wide portions at both end sides in the extension direction,
The pair of strong axis restraint members are provided over substantially the entire length of the narrow width portion in the extending direction.
Buckling-restrained structural material.

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