JP7520689B2 - Damper Structure - Google Patents

Description

The present invention relates to a damper structure.

There are various types of damping materials that are installed in buildings such as seismically isolated buildings and vibration-controlled buildings to absorb the vibration energy generated in the building during an earthquake and provide a damping effect to the building.

For example, damping materials include lead dampers and steel dampers for seismic isolation, but when these dampers are subjected to repeated deformation, their shape can change significantly, causing changes in their hysteresis characteristics or even causing the dampers to break, making it highly likely that they will need to be replaced after an earthquake.

For example, damping materials include oil dampers and viscous dampers for seismic isolation, as well as oil dampers, viscous dampers, viscoelastic dampers, and steel dampers for vibration control. However, these dampers only provide a damping effect in one horizontal direction, so in order to provide the same damping effect in two horizontal directions on a building, it is necessary to install twice the number of dampers.

Furthermore, for example, there are damping bearings such as high damping rubber bearings, rubber bearings with lead plugs, and rubber bearings with tin plugs as damping members. These damping bearings provide a damping effect in two horizontal directions, but if, for example, these damping bearings are additionally installed between the beams of the lower floor and the beams of the upper floor, fluctuating axial forces will act on the damping bearings during an earthquake. For this reason, there is concern that the damping bearings will undergo horizontal deformation and surface pressure fluctuations during an earthquake, which will cause the damping characteristics of the damping bearings to fluctuate. In addition, because damping bearings are additionally installed between the beams of the lower floor and the beams of the upper floor and are in a state where long-term axial forces are hardly applied to them, there is concern that they will easily go into a tensile state and break.

This problem is more severe the closer the damping bearing is to the outer edge of the building, but it is generally desirable to install dampers at the outer edge of the building in order to reduce the building's twisting behavior.

In response to this, Patent Document 1 discloses a support device that forms a gap on the upper surface of an upper flange plate provided on the top of the elastic body, preventing the vertical load of the upper structure from acting on the elastic body.

JP 2002-38418 A

However, in this bearing device, the elastic body undergoes shear deformation when a horizontal force acts on the upper flange plate, putting the elastic body in the same stress state as a cantilever beam, causing large bending deformation and large strain at the lower end, making it impossible to achieve stable damping performance.

Taking the above facts into consideration, the present invention aims to provide stable damping performance in two horizontal directions.

The damper structure according to the first aspect is a damper structure provided between a lower structure and an upper structure that are constructed so as to be relatively movable in the horizontal direction, and includes an axial member protruding downward from the upper structure or upward from the lower structure, a plurality of damping materials that exhibit damping performance in two horizontal directions and are arranged around the axial member with their lower ends fixed to the lower structure or their upper ends fixed to the upper structure, a connecting member having a hole into which the axial member is inserted and to which the upper ends or lower ends of the plurality of damping materials arranged around the axial member are fixed, and a load transmitting section that is provided on the inner circumferential surface of the hole or the outer circumferential surface of the axial member and transmits a horizontal force from the axial member to the connecting member at a height corresponding to the center position of the damping material in the height direction of the damping material.

According to the damper structure of the first aspect, when the lower structure and the upper structure move relative to each other in the horizontal direction due to an earthquake or the like, a horizontal force is transmitted from the shaft member to the connecting member by the load transmission part at the height of the center position of the damping material in the height direction of the damping material.

In addition, the upper or lower end of the damping material is fixed to a connecting member, and the upper structure or lower structure is not directly connected to the damping material in the vertical direction, so long-term vertical forces from the upper structure or vertical forces during earthquakes do not act directly on the damping material.

This allows only horizontal forces to act on the damping material without applying fluctuating axial forces, allowing the damping material to exhibit stable damping performance in two horizontal directions.

In addition, since multiple damping materials are arranged around the shaft member, the damper (damper structure) of this embodiment is able to exhibit stable damping performance in two horizontal directions without any torsional moment being applied to it.

The damper structure according to the second aspect is the damper structure according to the first aspect, in which the load transmission part is configured by a bearing or a sliding material that allows vertical movement and is provided on the inner circumferential surface of the hole or the outer circumferential surface of the shaft member.

The damper structure according to the second aspect reliably transmits only horizontal forces from the shaft member to the connecting member without transmitting vertical loads, by using a bearing or sliding material that allows vertical movement and is provided on the inner circumferential surface of the hole or the outer circumferential surface of the shaft member.

The damper structure according to the third aspect is the damper structure according to the first or second aspect, in which the damping material is a damping support that exhibits damping performance in two horizontal directions.

The damper structure according to the third aspect allows the damping bearing to provide stable damping performance in two horizontal directions.

The damper structure according to the fourth aspect is the damper structure according to the first or second aspect, in which the damping material is a block member made of a viscoelastic body, or a viscoelastic damper made by alternately laminating a viscoelastic body and a steel plate.

The damper structure according to the fourth aspect can provide stable damping performance in two horizontal directions using a viscoelastic damper constructed by alternately stacking a block member made of a viscoelastic material or a viscoelastic material and a steel plate.

The present invention has the above configuration, so it can provide stable damping performance in two horizontal directions.

FIG. 1 is a cross-sectional view showing a damper structure according to an embodiment. This is a cross-sectional view taken along line 2-2 of Figure 1. FIG. 4 is a cross-sectional view showing a connecting member according to one embodiment. FIG. 1 is a cross-sectional view showing a damper structure according to an embodiment. FIG. 2 is a front view showing a mechanical model of a damper structure according to an embodiment. FIG. 2 is a moment diagram of a damper structure according to one embodiment. FIG. 11 is a front view showing a mechanical model of a damper structure as a comparative example. FIG. 11 is a moment diagram of a damper structure as a comparative example. 9A to 9E are plan views showing variations of a connecting member according to one embodiment. 10A and 10B are plan views showing variations of the connecting member according to one embodiment. 11A and 11B are plan views showing variations of the connecting member according to one embodiment. 11A to 11C are cross-sectional views showing variations of a load transmitting portion according to an embodiment. 6A to 6C are cross-sectional views showing variations of a hole according to an embodiment. 6A to 6C are cross-sectional views showing variations of a hole according to an embodiment. 1A to 1C are cross-sectional views showing variations of a damper structure according to an embodiment. 1A to 1C are cross-sectional views showing variations of a damper structure according to an embodiment.

The damper structure according to one embodiment will be described below with reference to the drawings.

(Damper structure)
As shown in the cross-sectional view of FIG. 1 and in FIG. 2, which is a cross-sectional view of line 2-2 of FIG. 1, the damper structure 10 is provided between a foundation slab 12 as a lower structure and a beam 14 of the upper floor as an upper structure, which are constructed so as to be movable relative to each other in the horizontal direction.

The damper structure 10 is composed of a shaft member 16, a high-damping rubber bearing 18 as a damping material, a connecting member 20, and a sliding member 22 as a load transmission part.

The shaft member 16 is made of a steel rod formed into a cylindrical shape, and a flange 24 at the upper end is fixed to the underside of the beam 14 with a bolt and protrudes downward from the beam 14.

The high-damping rubber bearings 18 are damping bearings that exhibit damping performance in two horizontal directions, and four of them are arranged around the shaft member 16 by bolting the lower flange 28 at the lower end onto the seat 26 provided on the foundation slab 12. In other words, the lower end of the high-damping rubber bearings 18 is fixed to the foundation slab 12.

The connecting member 20 is a concrete member that is formed into a square plate shape in plan view and has a rigidity that is sufficiently greater than the rigidity of the high-damping rubber bearing 18. In addition, a circular through hole 30 is formed in the center of the connecting member 20 as a hole that passes through the connecting member 20 vertically, and the shaft member 16 is inserted into this through hole 30.

The upper flange 32 provided on the upper end of the high-damping rubber bearing 18 is bolted to the underside of the connecting member 20. In other words, the upper ends of the four high-damping rubber bearings 18 arranged around the shaft member 16 are fixed to the connecting member 20.

As shown in Figures 2 and 3, the sliding member 22 is a ring-shaped Teflon (registered trademark) plate that is attached to the inner circumferential surface 34 of the through hole 30. The shaft member 16 is able to slide up and down in the vertical direction on the inner circumferential surface 36 of the sliding member 22, so that almost no vertical force or moment is transmitted from the shaft member 16 to the connecting member 20, and only horizontal force is transmitted.

As shown in the cross-sectional view of FIG. 4, the sliding member 22 is provided at a height h at the center position of the high-damping rubber bearing 18 in the height direction of the high-damping rubber bearing 18, where the horizontal force P is transmitted from the shaft member 16 to the connecting member 20.

As shown in Figures 2 and 4, the four high-damping rubber bearings 18 are arranged in a balanced manner around the shaft member 16 so that no torsional moment is applied to the damper (damper structure 10) of this embodiment when a horizontal force P is transmitted from the shaft member 16 to the connecting member 20.

(effect)
Next, the effects of this embodiment will be described.

According to the damper structure 10 of this embodiment, as shown in FIG. 4, when the foundation slab 12 and the beam 14 move relative to each other in the horizontal direction due to an earthquake or the like, a horizontal force P is transmitted from the shaft member 16 to the connecting member 20 by the sliding member 22 acting as a load transmission part at a height h at the center position of the high-damping rubber bearing 18 in the height direction of the high-damping rubber bearing 18.

In addition, the upper end of the high-damping rubber bearing 18 is fixed to the connecting member 20, and the beam 14 and the high-damping rubber bearing 18 are not directly connected in the vertical direction, so long-term vertical forces and vertical forces during earthquakes do not act directly on the high-damping rubber bearing 18 from the beam 14.

This allows only horizontal force P to act on the high damping rubber bearing 18 without applying fluctuating axial force, allowing the damping material to exhibit stable damping performance in two horizontal directions.

To explain in detail how fluctuating axial forces do not act on the high-damping rubber bearings 18, as shown in the front view of FIG. 5, the mechanical model of the damper structure 10 is the mechanical model 38. The mechanical model 38 is configured with the high-damping rubber bearings 18 supported on the foundation slab 12 and the connecting member 20, with the distance between the two high-damping rubber bearings 18 being L, the height of the high-damping rubber bearings 18 being H, the height of the rigid horizontal plate portion of the connecting member 20 being D, and the length from the lower surface of the rigid horizontal plate portion of the connecting member 20 to the position where the horizontal force P is transmitted to the connecting member 20 (= the length from the lower surface of the rigid horizontal plate portion of the connecting member 20 to the height h of the center position of the high-damping rubber bearing 18) being H/2.

As shown in the moment diagram 40 in Figure 6, a moment M (hatched area) is generated in the high-damping rubber bearing 18 and the connecting member 20 in the dynamic model 38.

As shown in this moment diagram 40, horizontal force P is transmitted to the connecting member 20 at height h, which is the center position of the high-damping rubber bearing 18 in the height direction of the high-damping rubber bearing 18. Also, because the rigidity of the connecting member 20 is sufficiently greater than the rigidity of the high-damping rubber bearing 18, the stress state generated in the high-damping rubber bearing 18 is close to the ideal state, and when horizontal force P acts on the high-damping rubber bearing 18, no accompanying fluctuating axial force is generated in the high-damping rubber bearing 18.

For example, as shown in the front view of FIG. 7, in the case of a mechanical model 42 that is configured with a high-damping rubber bearing 18 supported on a foundation slab 12 and a connecting member 20, and a horizontal force P is transmitted to the connecting member 20 at a position above the high-damping rubber bearing 18, if the distance between the two high-damping rubber bearings 18 is L, the height of the high-damping rubber bearing 18 is H, the height of the rigid horizontal plate part of the connecting member 20 is D, and the length from the upper surface of the rigid horizontal plate part of the connecting member 20 to the position where the horizontal force P is transmitted to the connecting member 20 is H/2, a moment M (shaded area) is generated in the high-damping rubber bearing 18 and the connecting member 20, as shown in the moment diagram 44 in FIG. 8, and an axial force F (= P × (H + D) / L) is generated in the high-damping rubber bearing 18.

In addition, according to the damper structure 10 of this embodiment, as shown in FIG. 3, the sliding member 22 provided on the inner circumferential surface 34 of the through hole 30 formed in the connecting member 20 can reliably transmit only horizontal forces from the shaft member 16 to the connecting member 20 without transmitting vertical loads.

Furthermore, according to the damper structure 10 of this embodiment, as shown in FIG. 1, by using high-damping rubber bearings 18 as the damping material, it is possible to achieve stable damping performance in two horizontal directions.

In addition, according to the damper structure 10 of this embodiment, as shown in FIG. 2, multiple high-damping rubber bearings 18 are arranged in a balanced manner around the shaft member 16, so that the high-damping rubber bearings 18 can provide stable damping performance in two horizontal directions without applying a torsional moment to the damper (damper structure 10) of this embodiment.

(Modification)
Next, a modification of the above embodiment will be described.

In the above embodiment, as shown in FIG. 2, an example is shown in which the connecting member 20 is a member formed into a square plate shape in plan, but the planar shape of the connecting member 20 may be any shape. Also, as shown in FIG. 2, an example is shown in which four high-damping rubber bearings 18 as damping materials are arranged around the shaft member 16, but the damping materials may be arranged in a balanced manner around the shaft member 16 so that a torsional moment is not applied to the damper (damper structure 10) due to the horizontal forces in two horizontal directions transmitted from the shaft member 16 to the connecting member 20. For example, the planar shape of the connecting member 20 and the arrangement of the high-damping rubber bearings 18 as damping materials may be as shown in the plan views of FIGS. 9(a) to (e) and 10(a) and (b) for the connecting members 46, 48, 50, 52, 54, 56, and 58. In the case of the connecting members 56 and 58 in Figures 10(a) and (b), by transmitting horizontal force from the shaft member 16 to the connecting members 56 and 58 at the height of the center position of the high-damping rubber bearing 18 in the height direction of the high-damping rubber bearing 18, fluctuating axial force is not applied to the high-damping rubber bearing 18, and the high-damping rubber bearing 18 can exhibit stable damping performance.

In the above embodiment, as shown in FIG. 2, one through hole 30 is formed in the connecting member 20, but multiple through holes 30 may be formed in the connecting member 20 as long as they are arranged in a balanced manner so that horizontal forces are transmitted from the shaft members 16 inserted into the through holes 30 to the connecting member 20 almost simultaneously. For example, the connecting members 60 and 62 shown in the plan views of FIG. 11(a) and (b) may be formed.

In addition, in the above embodiment, as shown in FIG. 1, an example was given in which the damping material was a high-damping rubber bearing 18, but the damping material may be any material that can exhibit stable damping performance in two horizontal directions. For example, the damping material may be a lead plug rubber bearing or a tin plug rubber bearing, which are damping bearings with damping performance among seismic isolation bearings, or may be a block member made of a viscoelastic material, or may be a viscoelastic damper constructed by alternately laminating a viscoelastic material and a steel plate, or may be a multi-stage shear type viscoelastic damper. In addition, for example, the damping material may have any planar shape, such as a circle, a square, a rectangle, etc.

In the above embodiment, as shown in FIG. 3, the sliding material 22 as the load transmission part provided on the inner peripheral surface 34 of the through hole 30 is made of a Teflon (registered trademark) plate material. However, the load transmission part may be any material that can reliably transmit only the horizontal force P from the shaft member 16 to the connecting member 20 without transmitting the vertical load. For example, the load transmission part may be made of a sliding material made of other materials such as steel, or may be made of a bearing 64 that allows vertical movement as shown in the cross-sectional view of FIG. 12. For example, the load transmission part may be made of a rubber material that softly deforms in the vertical direction when in contact with the shaft member 16, transmits the horizontal force to the connecting member 20 but transmits almost no axial force (transmits only a small axial force from the shaft member 16 to the connecting member 20). Furthermore, the load transmission part may be provided on the inner peripheral surface of the through hole 30 or on the outer peripheral surface of the shaft member 16.

In addition, in the above embodiment, as shown in FIG. 1, the hole into which the shaft member 16 is inserted is a through hole 30 that passes vertically through the connecting member 20. However, as shown in the cross-sectional view of FIG. 13, the hole may be a bottomed hole 70, so long as there is a vertical clearance 68 between the lower surface of the shaft member 16 and the upper surface of the bottom portion 66.

Also, as shown in the cross-sectional view of FIG. 14, a sliding material 22 may be provided on the inner circumferential surface 34 of the through hole 30 so that a horizontal clearance 74 is provided between the inner circumferential surface 36 of the sliding material 22 and the outer circumferential surface 72 of the shaft member 16, or a sliding material 22 may be provided on the outer circumferential surface 72 of the shaft member 16 so that a horizontal clearance is provided between the outer circumferential surface of the sliding material 22 and the inner circumferential surface 34 of the through hole 30.

In this way, the damper structure 10 can function as a fail-safe mechanism that provides additional stiffness and damping to the building from a given displacement during a major earthquake.

In the above embodiment, as shown in FIG. 1, the connecting member 20 is made of concrete, but the connecting member 20 may have a rigidity sufficiently greater than that of the high-damping rubber bearing 18. For example, the connecting member 20 may be a member made of steel such as H-shaped steel or thick steel plate, or may be a member made of reinforced concrete integrally provided on the inside of a frame member made of steel such as H-shaped steel. The cross-sectional view of FIG. 15 shows an example of a damper structure 76 provided between a lower floor beam 80 as the lower structure and an upper floor beam 82 as the upper structure, with a connecting member 78 made of steel plate.

In the above embodiment, as shown in FIG. 1, an example was shown in which the damper structure 10 was provided between the foundation slab 12 as the lower structure and the beam 14 of the upper floor as the upper structure, but the damper structure 10 may be provided between the lower structure and the upper structure.

For example, if the damper structure 10 is provided between the lower floor beams as the lower structure and the upper floor beams as the upper structure, it can be used as a vibration damper that is placed in a column-beam frame and provides stable damping performance in two horizontal directions. Conventional brace-type vibration dampers placed in a column-beam frame can only provide damping performance in one horizontal direction.

In addition, in the above embodiment, as shown in FIG. 1, a high-damping rubber bearing 18 as a damping material is fixed and arranged on a seat 26 provided on a foundation slab 12 as a lower structure, and an axial member 16 is fixed and protruded from the underside of a beam 14 as an upper structure, but the damping material and axial member may be fixed directly to the lower structure or upper structure, or may be fixed to a connecting structure provided on the lower structure or upper structure.

In the above embodiment, as shown in FIG. 1, an example of a damper structure 10 is shown in which the lower end of a high-damping rubber bearing 18 as a damping material is fixed to a foundation slab 12 as a lower structure, and an axis member 16 is protruded downward from a beam 14 of the upper floor as an upper structure. However, the damper structure may be a damper structure 84 in which the configuration of the damper structure 10 is inverted, as shown in the cross-sectional view of FIG. 16.

The damper structure 84 is provided between the foundation slab 12 as a lower structure constructed to be relatively movable in the horizontal direction and the beams 14 of the upper floor as an upper structure, and includes an axis member 16 protruding upward from the foundation slab 12, a plurality of high-damping rubber bearings 18 as damping materials that exhibit damping performance in two horizontal directions and are installed around the axis member 16 with their upper ends fixed to the beams 14, a connecting member 20 having a through hole 30 as a hole portion into which the axis member 16 is inserted and to which the lower ends of the plurality of high-damping rubber bearings 18 installed around the axis member 16 are fixed, and a sliding member 22 as a load transmitting portion that is provided on the inner surface of the through hole 30 or the outer surface of the axis member 16 and transmits a horizontal force from the axis member 16 to the connecting member 20 at a height s of the center position of the high-damping rubber bearing 18 in the height direction of the high-damping rubber bearing 18.

Although one embodiment of the present invention has been described above, the present invention is not limited to this embodiment, and one embodiment and various modified examples may be used in appropriate combination, and the present invention may of course be embodied in various forms without departing from the spirit of the present invention.

10, 76, 84 Damper structure 12 Foundation slab (substructure)
14, 82 Beam (superstructure)
16 Shaft member 18 High damping rubber bearing (damping material)
20, 46, 48, 50, 52, 54, 56, 58, 60, 62, 78 Connecting member 22 Sliding member (load transmission part)
30 through hole (hole)
34 Inner circumferential surface 64 Bearing (load transmission part)
70 Hole (hole)
80 Beam (lower structure)
P horizontal force h, s height

Claims (4)

A damper structure provided between a lower structure and an upper structure that are constructed so as to be movable relative to each other in a horizontal direction,
A shaft member protruding downward from the upper structure or upward from the lower structure;
A plurality of damping materials having lower ends fixed to the lower structure or upper ends fixed to the upper structure and arranged around the shaft member, the damping materials exerting damping performance in two horizontal directions;
a connecting member having a hole into which the shaft member is inserted and to which upper ends or lower ends of a plurality of the damping materials arranged around the shaft member are fixed;
a load transmission portion provided on an inner peripheral surface of the hole or an outer peripheral surface of the shaft member, the load transmission portion transmitting a horizontal force from the shaft member to the connecting member at a height of a center position of the damping material in a height direction of the damping material;
A damper structure having the above structure. The damper structure according to claim 1, wherein the load transmission part is configured by a bearing or a sliding material that allows vertical movement and is provided on the inner circumferential surface of the hole or the outer circumferential surface of the shaft member. The damper structure according to claim 1 or 2, wherein the damping material is a damping support that exhibits damping performance in two horizontal directions. The damper structure according to claim 1 or 2, wherein the damping material is a block member made of a viscoelastic material, or a viscoelastic damper made by alternately laminating a viscoelastic material and a steel plate.