JP2022053009A - Structural member - Google Patents

Abstract

To provide a structural member preventing a stiffener from being cracked and being damaged when a steel plate bends through compression in a longitudinal direction.SOLUTION: A buckling binding brace 4 is provided with a steel plate 5 and a stiffener 6. The steel plate 5 is allowed to be assembled in a building and the like and has a specific length. The stiffener 6 is made from wooden material and placed on both sides of the steel plate 5 in a thickness direction and extends in the same direction with the steel plate 5. The buckling binding brace 4 is provided with a bolt 9, a nut 10, and a washer 18. The bolt 9 is inserted in each of through-holes 12 of the stiffeners 6 placed on both sides of the steel plate 5 in the longitudinal direction. The washer 18 is attached on as well as the nut 10 is screwed in both end parts of the bolt 9. Tightening the nut 10 pushes the stiffeners 6 to each other in a closer direction to push the steel plate 5. In this way, creation of a gap between the steel plate 5 and the stiffener 6 (bottom surface 11a) is suppressed.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to structural materials incorporated into structures such as buildings.

Structural materials are incorporated into structures such as buildings. Structural materials include frame materials such as columns and beams. Structural materials also include braces to reinforce the structure. The braces are arranged between the frames, that is, between the columns and beams. Patent Document 1 discloses a buckling restraint brace as a kind of the above brace. By incorporating this buckling restraint brace into a structure such as a building, the strength and rigidity of the structure can be increased.

The buckling restraint brace includes a steel plate, a stiffener, and a connecting member. The steel plate can be incorporated into the structure and has a predetermined length. The stiffener is for suppressing buckling of the steel sheet when the steel sheet is compressed in the longitudinal direction. The stiffeners are arranged on both sides of the steel plate in the thickness direction and extend in the same direction as the steel plate. A spacer plate is arranged next to the steel plate in the width direction. The spacer plate is located between the stiffeners arranged on both sides in the thickness direction of the steel plate. The connecting member penetrates the stiffeners arranged on both sides in the thickness direction of the steel plate, and connects the stiffeners to each other. When the steel sheet is compressed in the longitudinal direction, the stiffener restrains the steel sheet. As a result, buckling of the steel sheet is suppressed.

The stiffener is made of wood-based material. Therefore, the buckling restraint brace can be made lighter, and the view and feel of the buckling restraint brace can be improved. When the buckling restraint brace is incorporated into a building having columns and beams made of wood-based material, the following effects can also be obtained. That is, the texture and characteristics of the buckling restraint brace and the columns and beams can be matched, and the entire building can be finished by making the best use of the texture and texture of wood.

Japanese Patent No. 6719199

By the way, when the steel sheet is curved due to compression in the longitudinal direction of the steel sheet, a portion of the steel sheet near the apex of the curve is pressed against the stiffener. The magnitude of the force that presses the above-mentioned portion against the stiffener is related to the size of the gap between the steel plate and the stiffener when compression in the longitudinal direction of the steel plate does not occur. That is, the larger the gap, the greater the force that presses the portion against the stiffener. If the force that presses the above-mentioned portion against the stiffener is large, the stiffener may crack. There is also the possibility that the stiffener will be scratched.

Hereinafter, means for solving the above problems and their actions and effects will be described.
The structural material that solves the above problems includes a steel plate, a stiffener, and a connecting member. The steel plate can be incorporated into the structure and has a predetermined length. The stiffener is made of a wood-based material, is arranged on both sides in the thickness direction of the steel plate, and extends in the same direction as the steel plate. The connecting member connects the stiffeners arranged on both sides of the steel plate in the thickness direction. When the stiffeners are connected to each other, the connecting member presses the stiffeners in a direction of approaching each other. The stiffeners are configured to press the steel sheet when they approach each other based on the connection by the connecting member.

According to this configuration, when the stiffeners arranged on both sides in the thickness direction of the steel sheet are connected by the connecting member, the connecting member presses the stiffeners in the direction of approaching each other. As a result, the stiffener presses the steel plate, so that it is possible to suppress the formation of a gap between the steel plate and the stiffener. When the steel sheet is curved due to compression in the longitudinal direction of the steel sheet, a portion of the steel sheet near the apex of the curve is pressed against the stiffener. By suppressing the formation of the gap between the steel plate and the stiffener, the force with which the portion is pressed against the stiffener can be suppressed to a small value. Therefore, it is possible to prevent the stiffener from being cracked or scratched by the force of pressing the portion against the stiffener.

In the above structural material, it is conceivable that the connecting member is in contact with the stiffening member via the urging member. When the stiffeners are connected to each other by the connecting member, the urging member is supposed to urge the stiffeners in a direction of approaching each other.

According to this configuration, when the stiffener shrinks due to secular variation, the stiffener approaches the steel plate side by the urging force of the urging member by the amount corresponding to the shrinkage. Therefore, even if the stiffener shrinks due to secular variation, it is possible to suppress the formation of a gap between the stiffener and the steel plate.

In the above structural material, the stiffener has a first surface corresponding to the steel plate and a second surface located next to the first surface and facing the stiffener on the opposite side of the steel plate. It is conceivable to have. The connecting member passes through the second surface of the stiffener in the thickness direction of the steel plate, and connects the stiffeners by pressing the stiffeners in a non-connected state in a direction approaching each other. It is said that. When the stiffeners are arranged so that there is no gap between the first surface and the steel plate under the non-connected state of the stiffeners, the stiffeners face the second surface and the second surface. It is configured so that there is a gap between it and the material.

According to the above configuration, the stiffeners can be pressed in the direction of approaching each other by the connecting member by the amount of the gap between the second surfaces of the stiffeners. As a result, the stiffener can be pressed against the steel plate, and it is possible to suppress the formation of a gap between the steel plate and the stiffener.

In the above structural material, it is conceivable to provide a shear resistance member between the stiffeners at a position separated from the steel plate. The shear resistance member is embedded in the stiffeners arranged on both sides in the thickness direction of the steel sheet, each passing through the second surface.

When the structural material is compressed in the longitudinal direction, a shearing force in the longitudinal direction is generated between the stiffeners due to the bending of the stiffener due to the steel plate pressing the stiffener. If only the connecting members receive such shearing forces, the number of connecting members must be increased to resist the shearing forces. As a result, the cost is increased due to the provision of a large number of connecting members to the structural material, and the appearance of the structural material is deteriorated.

According to the above configuration, when the structural material is compressed in the longitudinal direction, the shearing force generated in the longitudinal direction between the stiffeners is applied not only to the connecting member but also to the shear resistance member. Therefore, it is not necessary to increase the number of connecting members in order to resist such shearing force. Further, since the shear resistance member is embedded in the stiffener through the second surface, it cannot be seen from the outside of the structural material. Therefore, it is possible to suppress the cost increase due to the provision of a large number of connecting members to the structural material and the deterioration of the appearance of the structural material.

In the above structural material, it is conceivable to sandwich a low friction sheet between the steel plate and the stiffener. The low friction sheet is supposed to reduce the frictional force generated between the steel plate and the stiffener.
When the steel plate is curved due to compression in the longitudinal direction of the structural material (steel plate), the portion of the steel plate near the apex of the curvature is pressed against the stiffener. A frictional force is generated by the pressing force at this time, and the compressive force in the longitudinal direction of the structural material increases due to the frictional force. The greater the frictional force, the greater the compressive force acting in the longitudinal direction of the structural material.

According to the above configuration, the low friction sheet is sandwiched between the stiffener and the steel plate so that no gap is formed between the stiffener and the steel plate. With this low friction sheet, the frictional force generated between the steel plate and the stiffener can be reduced. Therefore, when the steel plate is curved due to compression in the longitudinal direction of the structural material (steel plate), the frictional force generated between the steel plate and the stiffener is reduced, so that the compressive force acting in the longitudinal direction of the structural material increases. Can be kept small.

A side view showing a buckling restraint brace incorporated in a structure such as a building. An exploded perspective view showing a buckling restraint brace. Sectional drawing which shows the buckling restraint brace. The schematic which shows the steel plate and the stiffener when the buckling restraint brace is compressed in the longitudinal direction. The graph which shows the experimental result about the buckling state of a steel plate when a load is applied in the longitudinal direction to a buckling restraint brace. Sectional drawing which shows the buckling restraint brace. Side view showing a buckling restraint brace. Side view showing another example of a buckling restraint brace.

[First Embodiment]
Hereinafter, the first embodiment in which the structural material is embodied as a buckling restraint brace will be described with reference to FIGS. 1 to 5.

As shown in FIG. 1, a frame member such as columns 1 and beams 2 is incorporated in a structure such as a building. A plurality of gusset plates 3 are attached to the frame material of the structure at a predetermined distance. A buckling restraint brace 4 is incorporated between the gusset plates 3. The buckling restraint brace 4 is for increasing the strength and rigidity of the structure.

As shown in FIG. 2, the buckling restraint brace 4 includes a steel plate 5 and a stiffener 6. The steel plate 5 has a predetermined length. A joining plate 7 is welded to the end of the steel plate 5. The joint plate 7 is orthogonal to the thickness direction of the steel plate 5. As shown in FIG. 1, the end portion of the steel plate 5 and the gusset plate 3 are fixed by the attachment plates 16 and 17. Specifically, the attached plate 16 is bolted to the end of the steel plate 5 and the gusset plate 3, and the attached plate 17 is bolted to the joint plate 7 and the gusset plate 3. As a result, both ends of the steel plate 5 are fixed to the gusset plate 3. As a result, the steel plate 5 is incorporated into the structure.

The stiffener 6 shown in FIG. 2 is for suppressing buckling of the steel plate 5 when the steel plate 5 is compressed in the longitudinal direction. The stiffeners 6 are arranged on both sides of the steel plate 5 in the thickness direction and extend in the same direction as the steel plate 5. As the stiffener 6, for example, laminated lumber is used. Such a stiffener 6 is formed of a plate 8 made of a wood-based material. Specifically, the plurality of plate members 8 are arranged so as to extend in the same direction as the steel plate 5. Then, the stiffener 6 is formed by stacking the plurality of plate members 8 in the width direction of the steel plate 5. As the stiffener 6, an orthogonal laminated lumber (cross laminated timber: CLT) or a single plate laminated lumber (laminated veneer lumber: LVL) can also be used.

The stiffener 6 includes a groove 11. The groove 11 is located so as to face the steel plate 5, and extends in the same direction as the steel plate 5. The bottom surface 11a of the groove 11 serves as a first surface located corresponding to the steel plate 5. The stiffener 6 includes a joint surface 6a. The joint surface 6a is located next to the groove 11 and extends in the same direction as the groove 11. The joint surface 6a serves as a second surface facing the stiffener 6 on the opposite side of the steel plate 5. The stiffener 6 includes a plurality of through holes 12. The through hole 12 extends in the thickness direction of the steel plate 5 and passes through the joint surface 6a. The through holes 12 are arranged at predetermined intervals in the extending direction of the groove 11.

The buckling restraint brace 4 includes a plurality of bolts 9. The bolt 9 is for connecting the stiffeners 6 arranged on both sides of the steel plate 5 in the thickness direction to each other. The bolts 9 are inserted into the through holes 12 of the stiffeners 6, respectively. Male threads are formed at both ends of the bolt 9. Washers 18 are attached to both ends of the bolt 9. Further, nuts 10 are screwed into both ends of the bolt 9. Then, when the nut 10 is tightened, the stiffeners 6 in the unconnected state are pushed by the bolt 9, the washer 18, and the nut 10 in the direction of approaching each other. As a result, the stiffeners 6 arranged on both sides of the steel plate 5 in the thickness direction are connected to each other. The bolt 9, the washer 18, and the nut 10 serve as a connecting member for connecting the stiffeners 6 to each other.

FIG. 3 shows before tightening the nuts 10 to connect the stiffeners 6 to each other, in other words, the stiffeners 6 are not connected to each other, and the stiffeners 6 are close to each other by the nuts 10. The buckling restraint brace 4 when the pressure is not applied in the direction of the buckling is shown. At this time, when the stiffener 6 is arranged so that the bottom surface 11a of the groove 11 comes into contact with the steel plate 5, a gap is created between the joint surface 6a of the stiffener 6 and the stiffener 6 facing the joint surface 6a. Occurs. That is, the depth of the groove 11 in the stiffener 6 is determined so as to be so. Therefore, when the nut 10 is tightened, the stiffeners 6 arranged on both sides of the steel plate 5 in the thickness direction are pushed by the nut 10 in the direction of approaching each other. As a result, the stiffeners 6 approaching each other press the steel plate 5. At this time, the steel plate 5 is sandwiched between the stiffeners 6 and is restrained. By restraining the steel plate 5 with the stiffener 6 in this way, it is possible to prevent the steel plate 5 from buckling during compression in the longitudinal direction. When the nut 10 is tightened, the joint surfaces 6a of the stiffeners 6 arranged on both sides of the steel plate 5 in the thickness direction may be in contact with each other or may be separated from each other.

Next, the action and effect of the buckling restraint brace 4 of the present embodiment will be described.
As shown in FIG. 4, when the steel plate 5 is curved due to compression in the longitudinal direction during an earthquake or the like, the portion P1 near the apex of the curve in the steel plate 5 is pressed against the stiffener 6. If the force that presses the portion P1 against the stiffener 6 is large, the stiffener 6 may be cracked. In addition, the stiffener 6 may be scratched. The magnitude of the force that presses the portion P1 against the stiffener 6 is the size of the gap between the steel plate 5 and the bottom surface 11a of the groove 11 in the stiffener 6 when compression in the longitudinal direction of the steel plate 5 does not occur. Involved. That is, the larger the gap, the greater the force that presses the portion P1 against the stiffener 6.

In the buckling restraint brace 4, the stiffener 6 is formed as follows. That is, before the nut 10 is tightened, when the stiffeners 6 are not pressed by the nuts 10 in the direction in which they approach each other, the bottom surface 11a of the groove 11 in the stiffener 6 comes into contact with the steel plate 5. , A gap is formed between the joint surface 6a of the stiffener 6 and the stiffener 6 facing the joint surface 6a. As such, the depth of the groove 11 in the stiffener 6 is defined. Further, bolts 9 for connecting the stiffeners 6 arranged on both sides of the steel plate 5 in the thickness direction pass through the joint surface 6a of the stiffener 6 in the thickness direction of the steel plate 5.

By tightening the nut 10, when the stiffeners 6 arranged on both sides of the steel plate 5 in the thickness direction are connected to each other, the stiffener 6 is connected by the nut 10 by the amount of the gap between the joint surfaces of the stiffener 6. It can be pressed in a direction that brings them closer to each other. As a result, the bottom surface 11a of the groove 11 in the stiffener 6 is pressed against the steel plate 5, and it is possible to suppress the formation of a gap between the steel plate 5 and the bottom surface 11a of the groove 11 in the stiffener 6. By suppressing the generation of this gap, the force with which the portion P1 is pressed against the stiffener 6 can be suppressed to a small size. Therefore, it is possible to prevent the stiffener 6 from being cracked or scratched by the force that presses the portion P1 against the stiffener 6.

FIG. 5 shows the experimental results of the buckling state of the steel plate 5 when a load is repeatedly applied to the buckling restraint brace 4 of the present embodiment in the longitudinal direction (stretching direction). In FIG. 5, the vertical axis represents the load, and the horizontal axis represents the amount of expansion / contraction of the steel sheet 5 in the longitudinal direction due to the action of the load. As can be seen from FIG. 5, the larger the amount of expansion and contraction acting on the buckling restraint brace 4, the larger the load on the steel sheet 5. Then, when the expansion / contraction amount becomes large, the steel plate 5 buckles. In the buckling restraint brace 4, it is possible to suppress the formation of a gap between the steel plate 5 and the bottom surface 11a of the groove 11 in the stiffener 6, so that the amount of expansion and contraction when buckling is caused in the steel plate 5 becomes large. .. In other words, the resistance of the buckling restraint brace 4 to the expansion and contraction amount can be increased.

According to the present embodiment described in detail above, the following effects can be obtained.
(1) When the steel plate 5 is curved due to compression in the longitudinal direction during an earthquake or the like, the stiffener 6 may be cracked due to the force of the portion P1 near the apex of the curvature of the steel plate 5 being pressed against the stiffener 6. It is possible to prevent the stiffener 6 from being scratched.

[Second Embodiment]
Next, the second embodiment of the structural material will be described with reference to FIG.
As shown in FIG. 6, the buckling restraint brace 4 of this embodiment includes a disc spring 19 and a low friction sheet 13.

The low friction sheet 13 is arranged between the steel plate 5 and the bottom surface 11a of the groove 11 in the stiffener 6. The low friction sheet 13 extends in the same direction as the groove 11. The low friction sheet 13 prevents a gap from being formed between the bottom surface 11a and the steel plate 5. The low friction sheet 13 is for reducing the frictional force generated between the steel plate 5 and the bottom surface 11a.

The disc spring 19 is arranged between the nut 10 and the washer 18. Then, when the nut 10 is tightened, the nut 10 comes into contact with the stiffener 6 via the disc spring 19 and the washer 18. The disc spring 19 urges the stiffeners 6 in a direction of approaching each other by tightening the nut 10. The disc spring 19 serves as an urging member having such a function.

When the stiffeners 6 are pressed toward each other by tightening the nut 10, the low friction sheet 13 is sandwiched between the steel plate 5 and the bottom surface 11a of the groove 11 in the stiffener 6. By sandwiching the low friction sheet 13 between the steel plate 5 and the bottom surface 11a, a gap is prevented from forming between the steel plate 5 and the bottom surface 11a. At this time, the stiffener 6 presses the steel plate 5 via the low friction sheet 13.

According to this embodiment, in addition to the effects of the first embodiment, the following effects can be obtained.
(2) As a secular variation of the stiffener 6, the stiffener 6 undergoes a reduction in volume due to the release of water or the like. When the volume of the stiffener 6 is reduced in this way, the stiffener 6 approaches the steel plate 5 side by the urging force of the disc spring 19 by the amount corresponding to the reduction. Therefore, even if the volume of the stiffener 6 is reduced due to secular variation, the formation of a gap between the stiffener 6 and the steel plate 5 is suppressed.

(3) When the steel plate 5 is bent by compression in the longitudinal direction of the buckling restraint brace 4, the portion P1 near the apex of the bend in the steel plate 5 is pressed against the stiffener 6. A frictional force is generated by the pressing force at this time, and the compressive force in the longitudinal direction of the buckling restraint brace 4 increases due to the frictional force. The greater the frictional force, the greater the compressive force acting in the longitudinal direction of the buckling restraint brace 4.

The frictional force generated between the steel plate 5 and the bottom surface 11a is reduced by the low friction sheet 13 sandwiched between them. Therefore, when the steel plate 5 is curved due to compression in the longitudinal direction of the buckling restraint brace 4, the frictional force generated between the steel plate 5 and the bottom surface 11a is reduced, so that the buckling restraint brace 4 acts in the longitudinal direction. The increase in compression force can be suppressed to a small level.

[Third Embodiment]
Next, a third embodiment of the structural material will be described with reference to FIG. 7.
As shown in FIG. 7, the buckling restraint brace 4 of this embodiment includes a shear resistance member 14. The shear resistance member 14 has a metal rod shape and is arranged between the bolts 9 arranged in the longitudinal direction of the buckling restraint brace 4. The shear resistance member 14 is embedded in the stiffeners 6 arranged on both sides of the steel plate 5 in the thickness direction by passing through the joint surface 6a.

According to this embodiment, in addition to the effects of the first embodiment, the following effects can be obtained.
(4) When the buckling restraint brace 4 is compressed in the longitudinal direction, the stiffeners 6 are arranged on both sides in the thickness direction of the steel plate 5 due to the bending of the stiffener 6 due to the steel plate 5 pressing the stiffener 6. A shearing force in the longitudinal direction is generated between the materials 6. If only the bolt 9 receives such a shearing force, the number of bolts 9 must be increased in order to resist the shearing force. As a result, the cost of providing the buckling restraint brace 4 with a large number of bolts 9 is high, and the appearance of the buckling restraint brace 4 is deteriorated.

However, when the buckling restraint brace 4 is compressed in the longitudinal direction, the shearing force generated in the longitudinal direction between the stiffeners 6 is applied not only to the bolt 9 but also to the shear resistance member 14. Therefore, it is not necessary to increase the number of bolts 9 in order to resist such a shearing force. Further, since the shear resistance member 14 is embedded in the stiffener 6 through the joint surface 6a, it cannot be seen from the outside of the buckling restraint brace 4. Therefore, it is possible to suppress the cost increase due to the provision of a large number of bolts 9 to the buckling restraint brace 4 and the deterioration of the appearance of the buckling restraint brace 4.

[Other embodiments]
The above embodiment can be changed as follows, for example. The above embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.

-In the first embodiment, as shown in FIG. 8, the groove 11 may be formed in only one of the stiffeners 6 arranged on both sides of the steel plate 5 in the thickness direction.
-In the first embodiment, the groove 11 does not necessarily have to be formed in the stiffener 6.

-In the second embodiment, only one of the disc spring 19 and the low friction sheet 13 may be provided.
-In the third embodiment, one shear resistance member 14 is provided between each bolt 9 as shown in FIG. 7, but a plurality of shear resistance members 14 may be provided between each bolt 9.

-The shear resistance member 14 does not necessarily have to be made of metal, but may be made of wood or bamboo.
-The shear resistance member 14 does not necessarily have to be rod-shaped, but may be plate-shaped.

-In the first embodiment and the third embodiment, the disc spring 19 of the second embodiment may be provided.
-In the first embodiment and the third embodiment, the low friction sheet 13 of the second embodiment may be provided.

-Instead of the disc spring 19, an elastic body such as rubber may be provided as an urging member.
-A screw or the like may be used as the fastening member.
-Although the buckling restraint brace 4 has been exemplified as a structural material, it may be used as a structural material for a frame material such as a column 1 and a beam 2.

1 ... Pillar 2 ... Beam 3 ... Gasset plate 4 ... Washer restraint brace 5 ... Steel plate 6 ... Stiffening material 6a ... Joint surface 7 ... Joint plate 8 ... Plate material 9 ... Bolt 10 ... Nut 11 ... Groove 11a ... Bottom surface 12 ... Penetration Hole 13 ... Low friction sheet 14 ... Sheep resistance member 16 ... Attached plate 17 ... Attached plate 18 ... Washer 19 ... Belleville spring

Claims (5)

It is equipped with a steel plate, a stiffener, and a connecting member.
The steel plate can be incorporated into a structure and has a predetermined length.
The stiffener is made of a wood-based material, is arranged on both sides of the steel plate in the thickness direction, and extends in the same direction as the steel plate.
The connecting member is a structural material that connects the stiffeners arranged on both sides of the steel plate in the thickness direction.
When the stiffeners are connected to each other, the connecting member presses the stiffeners in a direction of approaching each other.
A structural material configured to press the steel plate when the stiffeners approach each other based on the connection by the connecting member. The connecting member is in contact with the stiffener via the urging member.
The structural material according to claim 1, wherein the urging member urges the stiffeners in a direction of approaching each other when the stiffeners are connected to each other by the connecting member. The stiffener has a first surface corresponding to the steel plate and a second surface located next to the first surface and facing the stiffener on the opposite side of the steel plate. And
The connecting member passes through the second surface of the stiffener in the thickness direction of the steel plate, and presses the stiffeners in a non-connected state in a direction approaching each other to press the stiffeners together. It is to be connected,
When the stiffeners are arranged so that no gap is formed between the first surface and the steel plate under the non-connected state of the stiffeners, the second surface and the second surface are the same. The structural material according to claim 1 or 2, wherein a gap is formed between the stiffener and the stiffener facing each other. A shear resistance member is provided between the stiffeners and at a position separated from the steel plate.
The structural material according to claim 3, wherein the shear resistance member is embedded in the stiffeners arranged on both sides of the steel plate in the thickness direction, each passing through the second surface. A low friction sheet is sandwiched between the steel plate and the stiffener.
The structural material according to any one of claims 1 to 4, wherein the low friction sheet reduces the frictional force generated between the steel plate and the stiffener.

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