JP2017089714A - Earthquake resistance improving elastic member, earthquake resistance improving structure and manufacturing method of earthquake resistance improving elastic member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an earthquake resistance improving elastic member in which an effect for restricting damage of a building is hardly lost and a limitation over its mounting location is hardly influenced when repeated loads of several times may act or even if an amplitude of oscillation is large.SOLUTION: A core member 2 acting as an earthquake resistance improving elastic member has an outer shape in which a flat plate body S is partially removed. The core member 2 comprises a pair of fixing portions 21, 22 positioned at both end portions in an extending direction [x-direction] of the flat plate body S and a main body part 23 arranged between a pair of fixing portions 21, 22. The main body part 23 has a shape bent back in a direction crossing with x-direction as seen at a plan view in respect to the flat plate body S and has a folding spring part 231 that can be extended or retracted elastically in the x-direction by a load in the x-direction.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an elastic member for improving earthquake resistance, a structure for improving earthquake resistance, and a method for producing an elastic member for improving earthquake resistance.

  In order to reduce the damage to a building when a large earthquake occurs, it is effective to attach a structure for improving earthquake resistance to a pillar or beam of the building in advance, such as a cane or brace.

  As shown in Patent Document 1, there is known a structure for improving earthquake resistance comprising a core formed by forming a slit in the central portion of a steel plate in plan view, and a member for preventing buckling deformation of the core. ing.

  As shown in Patent Document 2, a structure for improving earthquake resistance including a leaf spring is also known.

Japanese Patent Laying-Open No. 2015-14100 JP 2005-350937 A

  The structure for improving earthquake resistance of Patent Document 1 absorbs the energy of earthquakes by the plastic deformation of the core material. The slit of the core material is formed in order to preferentially plastically deform the portion, and is not for giving an elastic restoring force to the core material.

  Such a structure for improving earthquake resistance shows the effect of suppressing damage to buildings for small-scale earthquakes, but the duration of shaking is long and many repeated loads are applied. If it is large, it is difficult to exert such an effect. This is because the core material has almost zero rigidity after plastic deformation and cannot return to the origin by the elastic restoring force.

  The structure for improving earthquake resistance of Patent Document 2 can exhibit an elastic restoring force by a leaf spring. However, it is necessary to install the leaf spring in a state in which the width direction is directed in the depth direction perpendicular to the longitudinal direction of both the columns and beams constituting the joint. For this reason, it can install only in the location which can ensure the depth corresponding to the width | variety of a leaf | plate spring.

  Moreover, since the structure for improving earthquake resistance of Patent Document 2 has a complicated structure in which a plurality of leaf springs are bundled, it takes time to manufacture.

  The present invention has been made in view of the above circumstances, and even when a large number of repeated loads are applied or when the amplitude of shaking is large, the effect of suppressing damage to the building is not easily lost, and the installation location is restricted. A first object is to provide an elastic member for improving earthquake resistance and a structure for improving earthquake resistance.

  Moreover, this invention makes it the 2nd objective to provide the manufacturing method of the elastic member for seismic improvement which can obtain the elastic member for seismic improvement easily.

The elastic member for improving earthquake resistance according to the first aspect of the present invention is:
An elastic member for improving earthquake resistance having an outer shape of a shape obtained by partially removing a flat plate,
A pair of attachment portions located at both ends of the plate-like body in the extending direction;
A body portion disposed between the pair of attachment portions, the body portion having a shape folded in a direction intersecting the extending direction in a plan view with respect to the flat plate-like body, and the extension by the load in the extending direction A body portion having a folding spring portion that is elastically expandable and contractable in the direction of movement;
Is provided.

  The main body is divided into a plurality of segments in the thickness direction of the flat body and the width direction orthogonal to the extending direction, and each of the segments has the folding spring portion, and the segments They may be configured to be elastically displaceable in a direction away from and in a direction toward each other in the width direction.

  The main body portion may have a structure in which a plurality of the folding spring portions are connected in the extending direction.

  The folding spring portion may have a shape folded in a rectangular shape outward in the width direction perpendicular to the thickness direction of the flat plate-like body and the extending direction.

  The pair of attachment portions and the main body portion may be integrally formed.

The structure for improving earthquake resistance according to the second aspect of the present invention is:
An elastic member for improving earthquake resistance according to the first aspect;
A buckling prevention member for preventing buckling deformation in the thickness direction of the plate-like body with respect to the compressive load in the extending direction of the elastic member for improving earthquake resistance;
Is provided.

  The buckling prevention member may sandwich the elastic member for improving earthquake resistance from both sides in the thickness direction of the flat plate-like body.

  The folding spring portion is configured to be able to bend outward from a position of a side surface of the flat plate body facing a thickness direction of the flat plate body and a width direction orthogonal to the extending direction. Also good.

The manufacturing method of the elastic member for improving earthquake resistance according to the third aspect of the present invention,
Forming a pair of attachment portions on both ends of the flat steel in the longitudinal direction by partially removing the flat steel; and
By partially removing the flat bar, a main body part connected to the pair of attachment parts at a middle part in the length direction of the flat bar, and in the plan view with respect to the flat bar, the length direction and Forming a body portion having a folded back spring portion that has a shape folded in an intersecting direction and elastically expandable and contractable in the length direction by the load in the length direction;
including.

  According to the elastic member for improving earthquake resistance according to the first aspect of the present invention and the structure for improving earthquake resistance according to the second aspect, the folding spring portion elastically expands and contracts in the extending direction. Compared to absorbing vibration, the effect of suppressing damage to the building is less likely to be lost even when a large number of repeated loads are applied or the amplitude of the vibration is large.

  In addition, since the elastic member for improving earthquake resistance has an outer shape in which the flat plate body is partially removed, for example, when installed in a joint composed of a column and a beam, the longitudinal direction of both the column and the beam It can install in the state which turned the thickness direction of the flat plate-like body in the depth direction orthogonal to the direction. That is, since it can be installed as long as the depth corresponding to the thickness can be secured, it is difficult to be restricted by the installation location.

  According to the manufacturing method of the elastic member for improving earthquake resistance according to the third aspect of the present invention, the elastic member for improving earthquake resistance can be easily obtained only by partially removing the flat bar.

It is a conceptual diagram which shows the installation aspect of the structure for earthquake resistance improvement which concerns on embodiment. It is a disassembled perspective view which shows the principal part of the structure for earthquake resistance improvement which concerns on embodiment. It is a top view of the core material of the structure for earthquake resistance improvement which concerns on embodiment. It is a fragmentary sectional view perpendicular | vertical to the x direction of the structure for earthquake resistance improvement which concerns on embodiment. It is a flowchart of the manufacturing method of the structure for earthquake resistance improvement which concerns on embodiment. It is a conceptual diagram which shows the effect | action of the core material of the structure for earthquake resistance improvement which concerns on embodiment. It is a conceptual diagram which shows the effect | action of the core material of the structure for earthquake resistance improvement which concerns on embodiment. It is a top view of the core material of the structure for earthquake resistance improvement which concerns on other embodiment. It is a top view of the core material of the structure for earthquake resistance improvement which concerns on other embodiment. (A) is a conceptual diagram which shows the other installation aspect of the structure for earthquake resistance improvement which concerns on embodiment, (B) is sectional drawing perpendicular | vertical to the y direction of the connection part of an attachment part and a plate. It is a fragmentary sectional view perpendicular | vertical to the x direction of the structure for earthquake resistance improvement which concerns on other embodiment. It is a graph of the result of having measured the relationship between the x direction load made to act on the core material of the structure for an earthquake resistance improvement which concerns on an Example, and the x direction displacement amount of a core material. It is a conceptual diagram which shows the conditions of the simulation for calculating | requiring the response with respect to the seismic wave of the structure for an earthquake resistance improvement which concerns on an Example. (A) is a graph of the simulation result which shows the response with respect to the seismic wave of a frame, (B) is the graph of the simulation result which shows the response with respect to the seismic wave of the frame which attached the structure for an earthquake resistance improvement which concerns on an Example. . It is a shading graph which expressed the value of Mises stress which arises in a core material with shading.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the figure, the same or corresponding parts are denoted by the same reference numerals.

  As shown in FIG. 1, the structure 1 for improving earthquake resistance according to the embodiment is slanted as a cane on a joint composed of a column 91 and a beam 92 of a building 90 to be improved for earthquake resistance. It can be used in the passed mode. The structure for improving earthquake resistance 1 is generally plate-shaped, and the thickness direction is directed in the depth direction (the direction perpendicular to the paper surface in FIG. 1) perpendicular to the longitudinal direction of both the column 91 and the beam 92. Installed.

  The structure for improving earthquake resistance 1 includes a core material 2 as an elastic member for improving earthquake resistance, and a buckling prevention member 3 for preventing buckling deformation of the core material 2. The core member 2 includes an attachment portion 21 attached to a plate 93 fixed to the beam 92 and an attachment portion 22 attached to a plate 94 fixed to the column 91. In addition, in FIG. 1, the part located behind the buckling prevention member 3 of the core material 2 was shown with the broken line (hidden line).

  A load caused by an earthquake or the like is applied to a direction in which the pair of attachment portions 21 and 22 of the core member 2 are opposed to each other (hereinafter referred to as a facing direction). Here, the load includes a tensile load and a compressive load.

  FIG. 2 is an exploded perspective view showing the main part of the structure 1 for improving earthquake resistance. An xyz orthogonal coordinate system is defined in which the facing direction is the x direction and the thickness direction is the z direction. The buckling prevention member 3 in FIG. 1 includes first and second buckling prevention members 31 and 32 that sandwich the core material 2 from both sides in the z direction.

  The first and second buckling prevention members 31 and 32 are fixed using a bolt 33 as a fixing means shown in FIG. The first and second buckling prevention members 31 and 32 are formed with a plurality of bolt insertion holes 31a and 32a through which the bolts 33 are inserted.

  FIG. 2 shows the core material 2 in a no-load state in which no load is applied in the x direction. The core material 2 has an outer shape in which the flat plate-like body S extending in the x direction is partially removed in a no-load state. The flat plate body S extends long in the x direction so that the x direction is the longitudinal direction, and the x direction as the extending direction of the flat plate body S is the longitudinal direction of the flat plate body S. But there is.

  Similar to the core material 2, the first and second buckling prevention members 31 and 32 also extend long in the x direction. However, the length of the core material 2 in the x direction is longer than the lengths of the first and second buckling prevention members 31 and 32 in the x direction. In the state where the first and second buckling prevention members 31 and 32 sandwich the core material 2, the attachment portions 21 and 22 located at both ends in the x direction of the core material 2 are the first and second buckling members, respectively. It protrudes outward in the x direction from the prevention members 31 and 32.

  The attachment portions 21 and 22 each have a flat shape parallel to the flat plate-like body S. These flat mounting portions 21 and 22 are fixed to the building in a state where substantially the entire flat surface (front surface or back surface) is in surface contact with the building (specifically, the plates 93 and 94 in FIG. 1). . A plurality of bolt insertion holes 21a and 22a through which bolts for fixing to the building are inserted are formed in the attachment portions 21 and 22, respectively.

  The core material 2 has a main body portion 23 at a portion sandwiched between the first and second buckling prevention members 31 and 32 between the pair of attachment portions 21 and 22. The main body portion 23 is formed integrally with the pair of attachment portions 21 and 22. Hereinafter, the configuration of the main body 23 will be described.

  As shown in FIG. 3, the main body 23 has two segments 23a in the width direction (y direction) orthogonal to the thickness direction (z direction) and the extending direction (x direction) of the flat plate S in FIG. And 23b. The segments 23a and 23b are separated in the y direction.

  Each of the segments 23a and 23b has a periodic connection structure in which a plurality of folding spring portions 231 having outer shapes that are congruent with each other in a plan view are connected in the x direction by a connection portion 232.

  Each connecting portion 232 extends in the x direction at a substantially central portion in the y direction of the main body portion 23.

  Each of the folding spring portions 231 has a U-shape that is folded in a rectangular shape outward in the width direction (y direction) of the main body portion 23. Specifically, each folding spring portion 231 includes a top portion 231a located on the outermost side in the width direction (y direction) of the main body portion 23, and a pair of leg portions 231b that connect the top portion 231a to the connecting portion 232. Have. The top portion 231a extends in the x direction, and each leg portion 231b extends in the y direction.

  The top part 231a and the connecting part 232 of one segment 23a are respectively opposed to the corresponding top part 231a and connecting part 232 of the other segment 23b in the y direction.

  Both ends of the segments 23a and 23b in the x direction are connected to the attachment portions 21 and 22, respectively. The connection position is the end of the attachment portions 21 and 22 in the y direction. Specifically, each of the segments 23a and 23b includes a leg portion 233 extending outward from the x-direction end of the connecting portion 232 in the x-direction both ends, and an x-direction from the y-direction end of the leg 233. And a connection portion 234 that extends in the direction and is connected to the attachment portion 21 or 22.

  In FIG. 3, a circle V indicated by a broken line indicates an insertion position of the bolt 33 of FIG. 1 inserted through the bolt insertion holes 31a and 32a of FIG. As illustrated, the bolt 33 is inserted between the folding spring portions 231 adjacent in the x direction. The insertion position of the bolt 33 is not particularly limited as long as it is a position that does not contact the main body portion 23.

  FIG. 4 is a partial cross-sectional view of the structure 1 for improving earthquake resistance at a position along the line AA in FIG. 3 and perpendicular to the x direction. The first buckling prevention member 31 is made of a grooved steel having a flat bottom plate portion 311 and side plate portions 312 that rise vertically from both widthwise sides of the bottom plate portion 311 and serve as stiffening ribs. Similarly, the second buckling prevention member 32 is also made of channel steel having a bottom plate portion 321 and side plate portions 322.

  The first and second buckling prevention members 31 and 32 face each other with the bottom surfaces of the bottom plate portions 311 and 321 facing each other, and sandwich the core material 2 between the bottom plate portions 311 and 321. , 35.

  The main body portion 23 and the bottom plate portions 311 and 321 are in surface contact. When a load in the x direction is applied to the core member 2, the main body portion 23 elastically resists frictional force between the bottom plate portions 311 and 321 in an xy plane parallel to the bottom plate portions 311 and 321. It is possible to bend (refer FIG.6 and FIG.7).

  With reference to FIG. 5, the manufacturing method of the structure 1 for improving earthquake resistance will be described below.

  First, a flat bar having a length equal to the length in the x direction of the core material 2 to be obtained, a width equal to the width in the y direction, and a thickness equal to the thickness in the z direction is prepared (step S11). In addition, the flat body S shown in FIG. 1 represents this flat steel. The flat steel (flat plate S) has a flat shape in which the thickness (the length in the z direction) is smaller than the width (the length in the y direction) and the length (the length in the x direction).

  Next, the removal process which removes a flat bar partially is performed (step S12). This step S12 is a process of forming a pair of attachment portions 21 and 22 at both ends in the lengthwise direction of the flat steel by removal processing, and a pair of attachment portions 21 and 22 at the middle portion in the lengthwise direction of the flat steel. Forming a main body portion 23 to be connected. In addition, the order of the process A and the process B is arbitrary, and the processes A and B can be performed simultaneously.

  In the process A, if the bolt insertion holes 21a (see FIG. 3) are formed in both ends of the flat steel in the length direction, the attachment portions 21 and 22 are obtained. In this case, as the removal process, a drilling process for forming the bolt insertion hole 21a is used.

  In the process B, the main body 23 is obtained by removing the other portions such that the folding spring portion 231, the connecting portion 232, the width direction extending portion 233, and the axial direction extending portion 234 are left. In this case, wire electric discharge machining is used as the removal machining. Flat steel is used as one electrode, and the discharge wire is used as the other electrode. A desired portion can be removed by scanning the penetration position of the discharge wire in a plane parallel to the surface of the flat bar while feeding the discharge wire in the thickness direction of the flat bar.

  In addition, the removal processing method is not particularly limited, and other than wire electric discharge processing, for example, punching processing or cutting processing may be used. Moreover, you may perform the finishing process which reduces the roughness of the surface which was the surface of the flat steel after the removal process, and the surface formed by the removal process. Further, another member may be connected to the obtained core material 2 by welding or the like.

  Next, the core material 2 obtained by removing the flat steel is sandwiched between first and second buckling prevention members 31 and 32 each made of groove steel, and fixed with bolts 33 and nuts 34 and 35. Then, the structure 1 for improving earthquake resistance is completed (step S13).

  Hereinafter, with reference to FIG.6 and FIG.7, the effect | action of the structure 1 for earthquake resistance improvement is demonstrated.

  FIG. 6A shows a state in which the folding spring portion 231 is elastically bent when a tensile load in the x direction is applied to the core member 2 due to an earthquake or the like. In this case, the folding spring portion 231 bends so that the leg portion 231b opens in the x direction. Thereby, it is realized that the mounting portions 21 and 22 in FIG. 1 are relatively displaced so as to be away from each other in the x direction.

  FIG. 6B shows a state in which the folding spring portion 231 is elastically bent when a compressive load in the x direction is applied to the core material 2. In this case, the folding spring portion 231 bends so that the leg portion 231b is closed in the x direction. Moreover, the top part 231a of the folding | returning spring part 231 bends outward rather than the side surface which faces the y direction of the flat body S of FIG. Thereby, it is realized that the attachment portions 21 and 22 in FIG. 1 are relatively displaced so as to approach each other in the x direction.

  As shown in FIG. 3, the bolt 33 in FIG. 4 is inserted in a position that does not hinder the bending of the main body portion 23, and is folded between the first and second buckling prevention members 31 and 32. Both sides of the spring portion 231 in the y direction are open. Therefore, in FIG. 6B, the top portion 231a of the folding spring portion 231 can be bent outward in the y direction from the side surface of the flat plate-like body S in FIG.

  FIG. 7A shows how the connecting portion 232 bends when a tensile load in the x direction is applied to the core material 2. In this case, the connecting portion 232 of one segment 23a and the connecting portion 232 of the other segment 23b are bent so as to approach each other in the y direction. This bending, combined with the bending of the folding spring portion 231 shown in FIG. 6 (A), contributes to increasing the relative displaceable amount of the attachment portions 21 and 22 in FIG. 1 in the direction away from each other.

  FIG. 7B shows a state in which the connecting portion 232 bends when a compressive load in the x direction is applied to the core material 2. In this case, the connection part 232 of one segment 23a and the connection part 232 of the other segment 23b are bent so as to be away from each other in the y direction. This bending, combined with the bending of the folding spring portion 231 shown in FIG. 6B, contributes to increasing the relative displaceable amount of the attachment portions 21 and 22 in FIG.

  As described above, according to the present embodiment, for example, the following effects can be obtained.

  (1) When a load in the x direction acts on the core material 2, the folding spring portion 231 elastically expands and contracts in the x direction, and at the same time, an elastic restoring force in the x direction acts on the building 90. For this reason, compared with the case where the vibration is absorbed by plastic deformation, the effect of suppressing damage to the building is less likely to be lost even when a large number of repeated loads are applied or the amplitude of the vibration is large.

  (2) The main body portion 23 is divided into segments 23a and 23b in the y direction, each of the segments 23a and 23b has a folding spring portion 231, and the connecting portions 232 of the segments 23a and 23b are mutually in the y direction. It is configured to be elastically displaceable in the direction of moving away and the direction of approaching. For this reason, compared with the case where the main-body part 23 is not divided | segmented into the segments 23a and 23b, the relative displacement amount of the attachment parts 21 and 22 in the x direction can be enlarged.

  (3) The main body portion 23 has a structure in which a plurality of folding spring portions 231 are connected in the x direction. For this reason, compared with the case where it has only one folding spring part 231, the relative displacement possible amount of the attaching parts 21 and 22 in the x direction can be increased.

  (4) The folding spring portion 231 sandwiched between the first and second buckling prevention members 31 and 32 is configured to be able to bend outward from the side surface of the flat body S facing the y direction. Has been. For this reason, the amount of relative displacement in the x direction of the attachment portions 21 and 22 can be increased.

  (5) Since the core material 2 has an outer shape obtained by partially removing the flat plate-like body S, as shown in FIG. The beam 92 can be installed in a state in which the z direction, that is, the thickness direction of the plate-like body S is directed in the depth direction orthogonal to both longitudinal directions of the beams 92. In other words, it can be installed as long as the depth corresponding to the thickness can be secured. For this reason, it is hard to receive restrictions of an installation location. Moreover, since the structure 1 for improving earthquake resistance requires only a small installation space, it can be easily realized in combination with other vibration dampers.

  (6) The core material 2 can be obtained easily and inexpensively by simply removing the flat steel.

  Although one embodiment of the present invention has been described above, the present invention is not limited to this. For example, the following modifications are possible.

  In the above embodiment, the buckling prevention member 3 is provided. However, the buckling due to the compressive force of the core material 2 is allowed, and the structural design can be performed ignoring the compressive resistance force, or only the tensile load acts on the core material 2. If not, the buckling prevention member 3 may not be provided. Only the core material 2 may be attached to the building 90 as an elastic member for improving earthquake resistance.

  In the above-described embodiment, the configuration in which the segments 23a and 23b are separated in the y direction in the no-load state is shown, but the segments 23a and 23b may have a portion that contacts in the y direction in the no-load state. For example, even if the connecting portions 232 of the segments 23a and 23b are in contact with each other in the y direction, as shown in FIG. 7B, an elastic displacement that separates the connecting portions 232 when a tensile load is applied is realized. The

  In the above-described embodiment, the bolt 33 is inserted into a position that does not hinder the bending of the folding spring portion 231. However, when the folding spring portion 231 is bent more than a certain amount, the bolt 33 is inserted into a position where it comes into contact with the bolt 33. The bending of the main body 23 may be regulated by the bolt 33.

  In the above embodiment, FIG. 1 shows an example in which the structure 1 for improving earthquake resistance is installed in a joint as a walking stick, but the structure 1 for improving earthquake resistance or the core material 2 is composed of adjacent columns and columns. It is also possible to install as a brace between the two, or between the beams. The structure 1 for improving earthquake resistance can be attached not only to the steel structure but also to a wooden structure or an RC structure. Moreover, the structure 1 or the core material 2 for improving earthquake resistance can be retrofitted to an existing building, or can be incorporated in a building in advance at the time of new construction.

  In the said embodiment, although the core material 2 was formed from the flat steel, if the raw material of the core material 2 shows the elasticity which can be used for an earthquake resistance improvement, it will not be specifically limited to steel. For example, the material of the core material 2 may be iron other than steel, or a metal or alloy other than iron.

  8A to 8E show modifications of the main body portion of the core material 2.

  As shown in FIG. 8A, the folding spring portion may be configured by a ring-shaped member 241, and a plurality of ring-shaped members 241 may be connected by a connecting portion 242. As described above, the main body does not necessarily have to be divided into a plurality of segments in the y direction.

  As shown in FIG. 8B, a folding spring portion 243 having a top portion 243a located on the outermost side in the y direction and a pair of leg portions 243b-1 and 243b-2 connecting the top portion 243a to the connecting portion 243c. At least one of the leg portions 243b-1 and 243b-2 may extend in a direction intersecting the y direction. In FIG. 8B, the leg portion 243b-2 extends in an oblique direction intersecting the y direction, and a sawtooth-shaped main body portion is configured.

  As shown in FIG. 8C, the shape and / or size of a certain folding spring portion 244 may be different from that of other folding spring portions 245. In this way, the folding spring portions do not necessarily have to be congruent with each other in plan view.

  As shown in FIG. 8D, with respect to the y direction, the connecting portion 246c in one segment 246 is located on the top portion 247a of the folding spring portion in the other segment 247 rather than the top portion 246a of the folding spring portion in the one segment 246. You may arrange | position in the near position. In FIG. 8D, the leg portion 246b of the folding spring portion in one segment 246 and the leg portion 247b of the folding spring portion in the other segment 247 face each other in the x direction. And the top part 246a of the folding | returning spring part in one segment 246 and the connection part 247c in the other segment 247 are facing the y direction.

  As shown in FIG. 8E, the leg portion 248b of the folding spring portion 248 has a substantially right-angled bent portion between the connecting portion with the top portion 248a and the connecting portion with the connecting portion 248c in plan view. May have a crank shape having two locations. In FIG. 8E, the leg portion 248b has a portion facing both the top portion 248a and the connecting portion 248c in the y direction.

  9A to 9E show still another modification of the main body portion of the core material 2.

  As shown in FIG. 9A, the folding spring portion 249 may have a shape folded back in a substantially V shape in plan view so as to have a corner portion facing outward in the y direction.

  As shown in FIG. 9B, the folding spring portion 250 may have a shape folded in a substantially U shape in a plan view so as to be convexly curved outward in the y direction.

  As shown in FIG. 9C, the position in the x direction may be shifted between the folding spring portion 231 of one segment and the folding spring portion 231 of the other segment.

  As shown in FIG. 9D, the folding spring portion 251 may have a shape folded in an oblique direction intersecting the x direction and the y direction in plan view.

  As shown in FIG. 9E, a shaft member 252 extending in the x direction may be disposed between one segment and the other segment. The shaft member 252 has an effect of preventing the core material 2 from bending in the y direction, for example. A gap is secured between both ends of the shaft member 252 in the x direction and the attachment portions 21 and 22, and the shaft member 252 does not hinder the relative displacement of the attachment portions 21 and 22 in the direction approaching each other. Further, a gap is also secured between both ends of the shaft member 252 in the y direction and the folding spring portion. The shaft member 252 is held in a state of being sandwiched between the first and second buckling prevention members 31 and 32 shown in FIG. 2 in the thickness direction. The shaft member 252 can also be obtained from the same flat bar as the flat bar for obtaining the core material.

  FIG. 10 (A) is a conceptual diagram showing another installation mode of the earthquake-proof structure 1. As shown in the drawing, the attachment portion 21 and the plate 93 may be connected using the accessory plate 81, and the attachment portion 22 and the plate 93 may be connected using the accessory plate 82.

  FIG. 10B is a cross-sectional view of the connecting portion between the attachment portion 21 and the plate 93 parallel to the xz plane. The accessory plate 81 includes a pair of front and back accessory plates 81a and 81b that sandwich the attachment portion 21 and the plate 93 in the thickness direction (z direction). In a state where the attachment portion 21 and the plate 93 are sandwiched between the attachment plates 81a and 81b, the attachment plates 81a and 81b and the attachment portion 21, and the attachment plates 81a and 81b and the plate 93 are coupled with bolts inserted in the z direction, respectively. Has been. Although not shown, the accessory plate 82 is also constituted by a pair of front and back accessory plates, and the connecting portion between the attachment portion 22 and the plate 94 is also configured in the same manner as in FIG.

  FIGS. 11A to 11C show other modified examples of the structure 1 for improving earthquake resistance.

  As illustrated in FIG. 11A, the inclusion 4 may be disposed between the core member 2 and the first and second buckling prevention members 31 and 32. As the inclusion 4, a friction force adjusting agent (for example, oil or adhesive) for adjusting the friction force between the core member 2 and the first and second buckling prevention members 31 and 32, For example, an elastic body (for example, rubber packing).

  As shown in FIG. 11B, the side plate 5 is disposed on both sides of the first and second buckling prevention members 31 and 32 in the y direction, and the side plate 5 and the first and second buckling prevention members 31 are arranged. And 32 may be fixed by a bolt 33 inserted in the y direction.

  In addition, if the width | variety of the 1st and 2nd buckling prevention members 31 and 32 is made wider than the width | variety of the core material 2, the elastic displacement to the y direction outward of the core material 2 is accept | permitted. Further, an opening that allows the folding spring portion 231 to protrude may be formed at a position of the side plate 5 that faces the folding spring portion 231.

  As shown in FIG. 11C, the core member 2 and the first and second buckling prevention members 31 and 32 sandwiching the core member 2 may be inserted into the hollow tubular body 6 made of a square steel pipe. . In this case, the bolt 33 and the nuts 34 and 35 are unnecessary.

〔Example〕
Examples will be described below.

  A flat steel made of high-strength steel H-SA700 specified in the Japan Iron and Steel Federation product standard was prepared. The flat steel has a thickness of 9 mm, a length of 1140 mm, and a width of 140 mm. The flat steel was subjected to wire electric discharge machining to obtain a core material 2 having a shape shown in FIG.

  The obtained core material 2 has the same thickness, length, and width as flat steel. The length of the main body 23 in the x direction is 760 mm. Each folding spring portion 231 has a length in the x direction of 80 mm. Each connecting portion 232 has a length in the x direction of 60 mm and a width of 10 mm, and an interval in the y direction between the connecting portions 232 is 10 mm.

  Next, the obtained core material 2 was sandwiched between first and second buckling prevention members 31 and 32 each made of grooved steel, and lightly bolted by hand tightening to obtain a structure 1 for improving earthquake resistance. .

  A tensile load and a compressive load were alternately and repeatedly applied in the x direction between the attachment portions 21 and 22 of the obtained structure 1 for improving earthquake resistance, and the amount of displacement in the x direction was measured.

  FIG. 12 is a graph showing the relationship between the measured displacement amount and the load. The horizontal axis represents the relative displacement amount in the x direction of the pair of attachment portions 21 and 22, and this value was measured by a displacement meter. The vertical axis represents the load in the x direction applied to the core material 2, and this value was measured by a load cell. As for the load, the compressive load was positive and the tensile load was negative. The load was changed stepwise so that the amount of displacement in the x direction was ± 5 mm, ± 10 mm, and ± 15 mm.

  As shown in the figure, it was confirmed that the elastic behavior was maintained within the range of the displacement amount in the x direction of about ± 15 mm. The rigidity of the core material 2 represented by the inclination of the graph is about 5 kN / cm. The slight nonlinear behavior shown in the graph is considered to be caused by friction between the core material 2 and the buckling prevention member 3.

  The maximum strain generated in the core material 2 is 15 / 1140≈1 / 67, and this value is almost equal to the strain imposed on a general building in a large earthquake. Thus, according to the structure 1 for improving earthquake resistance according to this example, it was confirmed that the elasticity is maintained even when the shaking is large and a large number of repeated loads are applied.

[Simulation 1]
The simulation for obtaining the response to the earthquake of the structure for improving earthquake resistance 1 according to the above embodiment was performed. The rigidity of the structure 1 for improving earthquake resistance was set to 5 kN / cm.

  FIG. 13 shows the simulation conditions. The pillars 95 and 95 are erected on the foundations 97 and 97, respectively, and the structure 1 for improving earthquake resistance is attached to the four corners of a gate-shaped frame in which a beam 96 is installed between the pillars 95 and 95. The height of the column 95 is 400 cm, the length of the beam 96 is 800 cm, and the length (the length in the x direction) of the structure 1 for improving earthquake resistance is about 141.4 cm.

The column 95 was a square steel pipe having a wall thickness of 12 mm and a side angle of 250 mm. The beam 96 was an H-shaped steel having an H dimension of 450 mm, a B dimension of 200 mm, a t1 dimension of 9 mm, and a t2 dimension of 14 mm. Yield strength of the material of the pillars 95 and beams 96 235N / mm ^2, Young's modulus was ^{2.05 × 10 5 N / mm 2} . Further, it is assumed that a concentrated weight of 50 kN exists at both ends of the beam 96 and a concentrated weight of 100 kN exists at the center of the beam 96.

  A seismic wave was given to the frame of the above configuration. The seismic wave was the same as that of the 1995 Hyogoken Nanbu Earthquake observed at the Kobe Ocean Meteorological Observatory (Kobe NS wave). The maximum ground motion acceleration of the seismic wave is 818 gal and the duration is 29.6 seconds.

  FIG. 14A is a graph showing, as a comparative example, a response when the seismic wave is given to the frame to which the structure for improving earthquake resistance 1 is not attached. The horizontal axis represents the displacement of the frame in the lateral direction (the length direction of the beam 96) of the beam 96 (hereinafter referred to as interlayer displacement), and the vertical axis represents the lateral shear force (hereinafter referred to as layer shear force). .)

  As shown in the figure, hysteresis is observed, but the displacement of the interlayer displacement in the positive direction is observed. The maximum displacement in the positive direction was 8.28 cm. Further, the upper part C1 of the graph representing the hysteresis is substantially horizontal, indicating that the rigidity of the frame is substantially zero in this part.

  FIG. 14B is a graph showing the response to the same seismic wave of the frame in which the structure 1 for improving earthquake resistance according to the example is attached to the four corners. As shown in the figure, the bias of the interlayer displacement in the positive direction is reduced. This indicates that the effect of returning to the origin by the elastic restoring force of the structure 1 for improving earthquake resistance is exhibited. The maximum positive displacement decreased to 6.93 cm. Furthermore, the slope of the upper part C2 of the graph representing the hysteresis is larger than the slope of the corresponding part C1 of the comparative example. This indicates that the rigidity of the frame is maintained. Thus, according to the structure 1 for improving earthquake resistance according to the example, it was confirmed that the effect of suppressing damage to the building was maintained even when a large earthquake occurred.

[Simulation 2]
For each of the core specimens A to H made of the same flat steel (H-SA700) and different in shape in plan view, one end in the x direction was fixed and a tensile load in the x direction was given to the other end. In some cases, the Mises stress generated in the specimen was calculated by elastic finite element analysis.

  15A to 15H show images in which the calculation results of Mises stress are expressed in shades. The portion where the Mises stress ratio is 0 is expressed in white, the portion where the Mises stress ratio is 1 is expressed in black, and the portion where the Mises stress ratio exceeds 0 and less than 1 is expressed in gray so that the closer to 1, the darker . The darker the color, the more concentrated the stress.

  FIG. 15A shows the analysis result of the specimen A. The test body A had the shape shown in FIG. The width of each of the top part, the leg part, and the connecting part constituting the folding spring part was 10 mm.

  FIG. 15B shows the analysis result of test B. Compared with the test body A, the test body B has one fewer folding spring parts.

  FIG. 15C shows the analysis result of the specimen C. Similarly to the test specimens A and B, the test specimen C has the shape shown in FIG. However, each width | variety of the top part which comprises a folding | returning spring part, a leg part, and a connection part was 20 mm.

  FIG. 15D shows the analysis result of the specimen D. The test body D had the shape shown in FIG. The width of each of the top part, the leg part, and the connecting part constituting the folding spring part was 10 mm.

  FIG. 15E shows the analysis result of the specimen E. The specimen E had a shape shown in FIG. The width of each of the top part, the leg part, and the connecting part constituting the folding spring part was 10 mm.

  FIG. 15 (F) shows the analysis result of the specimen F. The test body F had a shape shown in FIG. The width of each of the top part, the leg part, and the connecting part constituting the folding spring part was 15 mm. Further, the length in the x direction of the top portion of the folding spring portion at the center in the x direction was twice that of the other folding spring portions.

  FIG. 15G shows the analysis result of the specimen G. The test body G had a shape shown in FIG. The width of each of the top part, the leg part, and the connecting part constituting the folding spring part was 15 mm.

  FIG. 15 (H) shows the analysis result of the specimen H. The test body H had a shape shown in FIG. The width of each of the top part, the leg part, and the connecting part constituting the folding spring part was 15 mm.

  Further, for each of the test bodies A to H, the displacement in the x direction (displacement at yield) and the load at that time (yield load) when any part reaches the Mises yield condition for the first time were calculated.

  Table 1 shows the calculation results. In Table 1, the width refers to the width of each of the top portion and the leg portion and the connecting portion constituting the folding spring portion.

  For example, when the calculation results of the test bodies A and B and the test body D are compared, it can be seen that the test bodies A and B can secure a larger displacement at yield than the test body D. In the test bodies A and B, the main body is divided into two segments in the y direction, and the segments are separated from each other in the y direction as described with reference to FIG. By being elastically displaceable.

  Moreover, the load at the time of yielding of the test body E having a sawtooth-shaped main body is significantly smaller than that of other test bodies having a rectangular folded spring portion. From this, it can be said that the folding spring portion preferably has a shape folded into a rectangle.

  The specimen C has the largest yield load, but the smallest yield displacement. If a displacement larger than the yield displacement is brought about, the elastic restoring force cannot be exhibited. Therefore, it is preferable that both the yield load and the yield displacement are large. From this viewpoint, it can be said that the specimens A, B, G, and H are preferable.

  Various embodiments and modifications can be made to the present invention without departing from the broad spirit and scope thereof. The above embodiment is for explaining the present invention, and does not limit the scope of the present invention. The scope of the present invention is shown not by the embodiments but by the claims. Various modifications within the scope of the claims and the scope of the equivalent invention are considered to be within the scope of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Structure for improving earthquake resistance, 2 ... Core material (elastic member for improving earthquake resistance), 3 ... Buckling prevention member, 4 ... Inclusion, 5 ... Measuring plate, 6 ... Hollow tubular body, 21, 22 ... Installation Part, 21a, 22a ... bolt insertion hole, 23 ... main body part, 23a, 23b ... segment, 31 ... first buckling prevention member, 31a, 32a ... bolt insertion hole, 32 ... second buckling prevention member, 33 ... bolts, 34, 35 ... nuts, 81, 81a, 81b, 82, 82a, 82b ... accessory plates, 90 ... buildings, 91, 95 ... pillars, 92, 96 ... beams, 93, 94 ... plates, 97 ... foundations, 231, 235, 236, 238 ... folding spring part, 232 ... connection part, 233 ... width direction extension part, 234 ... axial direction extension part, 231a ... top part, 231b, 233 ... leg part, 234 ... connection part, 241 ... Ring-shaped member, 242 ... Connection part, 243 ... Fold Return spring part, 243a ... top part, 243b-1,243b-2 ... leg part, 243c ... connecting part, 244,245 ... folding spring part, 246 ... segment, 246a ... top part, 246b ... leg part, 246c ... connecting part, 247 ... Segment, 247a ... Top, 247b ... Leg, 247c ... Connection part, 248 ... Folding spring part, 248a ... Top part, 248b ... Leg part, 248c ... Connection part, 249, 250, 251 ... Folding spring part, 252 ... Shaft member, 311, 321... Bottom plate portion, 312, 322... Side plate portion, S.

Claims (9)

An elastic member for improving earthquake resistance having an outer shape of a shape obtained by partially removing a flat plate,
A pair of attachment portions located at both ends of the plate-like body in the extending direction;
A body portion disposed between the pair of attachment portions, the body portion having a shape folded in a direction intersecting the extending direction in a plan view with respect to the flat plate-like body, and the extension by the load in the extending direction A body portion having a folding spring portion that is elastically expandable and contractable in the direction of movement;
An elastic member for improving earthquake resistance.   The main body is divided into a plurality of segments in the thickness direction of the flat body and the width direction orthogonal to the extending direction, and each of the segments has the folding spring portion, and the segments The elastic member for improving seismic resistance according to claim 1, wherein the elastic members are configured to be elastically displaceable in a direction in which they are separated from each other in the width direction and a direction in which they are approached.   The elastic member for improving earthquake resistance according to claim 1 or 2, wherein the main body has a structure in which a plurality of the folding springs are connected in the extending direction.   The earthquake resistance according to any one of claims 1 to 3, wherein the folding spring portion has a shape folded in a rectangular shape outward in the width direction perpendicular to the thickness direction of the flat plate-like body and the extending direction. Elastic member for improvement.   The elastic member for improving earthquake resistance according to any one of claims 1 to 4, wherein the pair of attachment portions and the main body portion are integrally formed. The elastic member for improving earthquake resistance according to any one of claims 1 to 5,
A buckling prevention member for preventing buckling deformation in the thickness direction of the plate-like body with respect to the compressive load in the extending direction of the elastic member for improving earthquake resistance;
A structure for improving earthquake resistance.   The structure for improving earthquake resistance according to claim 6, wherein the buckling preventing member sandwiches the elastic member for improving earthquake resistance from both sides in the thickness direction of the flat plate-like body.   The folding spring portion is configured to be able to bend outward from a position of a side surface of the flat plate body facing a thickness direction of the flat plate body and a width direction orthogonal to the extending direction. Item 8. The structure for improving earthquake resistance according to Item 6 or 7. Forming a pair of attachment portions on both ends of the flat steel in the longitudinal direction by partially removing the flat steel; and
By partially removing the flat bar, a main body part connected to the pair of attachment parts at a middle part in the length direction of the flat bar, and in the plan view with respect to the flat bar, the length direction and Forming a body portion having a folded back spring portion that has a shape folded in an intersecting direction and elastically expandable and contractable in the length direction by the load in the length direction;
A method for producing an elastic member for improving earthquake resistance, comprising: