JPH0819788B2 - Elastic-plastic damper - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a damper used in a seismic isolation or vibration control structure of a building, and more specifically, for absorbing energy such as an earthquake by deformation, The present invention relates to an elasto-plastic damper that utilizes the characteristics of an elasto-plastic material that is elastic in small deformation and plastic in large deformation.

[Prior Art] Conventional elasto-plastic dampers are often used individually or in combination of bending, shearing, and twisting deformations of metal materials such as steel and lead.

A metal material, even if it is bent, sheared or twisted, deforms when the strain exceeds a certain level.
In the elasto-plastic damper with the conventional mechanism, the strain of the plastically deformed part increases as the amount of deformation of the damper increases, and the occurrence of plastic strain and its repetition concentrate on a specific cross section. The practical limit of the plasticity rate is about 5-10. In order to increase the deformability, it is necessary to increase the elastic deformation amount, but in this case, the function as a damper cannot be exhibited against the action of a small disturbance. On the contrary, in order to exert the function as a damper against the action of a small disturbance, it is necessary to set the elastic limit small, and in that case, when a large disturbance acts, geometrical nonlinearity,
In addition to being strongly affected by factors that are difficult to quantify, such as the strain effect, the deformability becomes poor, and the possibility of fracture is extremely high.

[Problems to be Solved by the Invention] The present invention was created in order to improve the fact that the existing elasto-plastic damper mechanism cannot retain stable hysteresis characteristics against repeated deformation at a large plasticity rate. The specific items were as follows.

A. Make sure that the bending strain is not concentrated at specific points of the elasto-plastic material, and that the large bending strain that directly affects the fracture does not occur over the entire cross section.

B. Always draw a stable hysteresis loop from a small plasticity rate to a large plasticity rate so that the yield strength and rigidity do not change significantly even if the amount of deformation and the number of repetitions increase.

C. To reduce the influence of geometrical non-linearity and make the mechanism easy to quantify analytically.

D. Restoring force characteristics should not be brittlely deteriorated.

[Means for Solving the Problems] The elasto-plastic damper of the present invention is one or a plurality of metallic materials and / or polymeric materials selected from mild steel, stainless steel, copper, lead and aluminum, or a composite material thereof. An elasto-plastic body formed and having a U-shaped portion, a guide wheel attached to the U-shaped portion of the elasto-plastic body and having an outer diameter approximately equal to its inner diameter, and a support member for fixing the leg portion of the elasto-plastic body The guide wheel is fixed to the support member by a wire, the elasto-plastic body is formed in a loop shape having U-shaped portions at both ends, and a pair of guide wheels is provided at both ends thereof. A direct axial force is applied to the elasto-plastic body, the elasto-plastic body is formed of two or more metals or polymer materials in a laminated structure, and a rubber layer is arranged between the layers. That is, elasto-plastic body, that are arranged and fixed between the arm member having a coupling means to the support member and the tip, and each said.

EXAMPLES Next, the present invention will be described in detail according to the examples shown in the accompanying drawings.

1 and 2 show a first embodiment of the present invention, in which 1 is a U-shaped member functioning as an elastoplastic body, and the U-shaped portion is associated with a guide wheel 2. Both ends are joined to the supporting member 3. 4 is a wire.

The inner diameter of the U-shaped portion of the U-shaped member 1 is set to be substantially equal to the outer diameter of the guide wheel 2. The U-shaped member 1 as an elasto-plastic body is mainly formed of a metal material having a relatively high ductility such as mild steel, stainless steel, copper, lead, aluminum, or a polymer material. When a material that is particularly soft, such as polymer material or lead, and whose elongation may increase as the bending deformation and the number of repetitions increases, such as a wire, the bending rigidity is low and the tensile rigidity is low. It is preferable to reinforce the material with a high material.

The cross-sectional shape of the U-shaped member 1 and the number of U-shaped members 1 to be arranged are not limited.

As shown in FIG. 3, when a force is applied along the axis of the U-shaped member 1 in the direction of the arrow, the shape of the U-shaped member 1 changes to an unstable shape such as a broken line as the deformation increases. In the embodiment shown in FIGS. 1 and 2, two U-shaped members 1 are arranged with their directions reversed, and a guide wheel 2 is inserted between them. In this case, when a force is applied as indicated by an arrow, it restrains each U-shaped member 1 from being deformed as shown by a broken line in FIG. 3, so that the entire U-shaped member 1 has a stable shape from U-shape to J-shape. Show changes.

When relative displacement occurs in the support member 3 in the direction of the arrow,
In the U-shaped member 1, as the guide wheel 2 rotates, the part in which the strain occurs or the part in which the strain is released moves and the overall shape changes from the U shape to the J shape, but the guide wheel 2 changes the curvature. Because of the restraint, it is possible to avoid the strain from being concentrated on a specific cross section. If the curvature of the guide wheel 2 is used in a range where the strain of the elasto-plastic material having the σ-ε relationship as shown in Fig. 6 is on the yield shelf, not only the yield strength of the damper can be easily estimated, but also the strain of the material Very stable energy absorption performance can be obtained without being affected by the effect. Moreover, this hysteresis loop has a great feature that the yield rigidity is almost zero and it is close to a perfect elasto-plastic form.

As the number of repeated loadings on the damper increases,
It is expected that a part of the U-shaped member 1 will break. In such a case, in order to prevent the guide wheel 2 from coming off and breaking the mechanism of the damper brittlely, and to continuously exhibit stable hysteresis characteristics, the guide wheel 2 is preliminarily provided with, for example, four wires. It is preferable to support the supporting member 3 by means of 4.

In assembling the damper, if the damper is mounted so that no gap is created between the support member 3 and the U-shaped member 1 and between the U-shaped member 1 and the guide wheel 2, the damper's proof strength will not change, but the initial rigidity will be higher. History characteristics can be obtained.

FIG. 4 shows a second embodiment of the present invention, in which U shown in FIGS. 1 and 2 is provided around two guide wheels 2.2 which are mounted with a constant spacing. Character member 1
By attaching the loop-shaped elasto-plastic body 5 made of the same material as the semicircular arc and the straight line and directly applying an axial force to this member, the same hysteresis characteristic as in the case of the first embodiment can be obtained. it can.

As shown in FIG. 5, the U-shaped member 1 (elastic-plastic body 5) preferably has a laminated structure, and further preferably has a composite structure using materials different in each layer. Although not shown, it is also preferable to dispose a rubber layer between the layers so as to cope with a slight dimensional change in the width direction.

7 to 9 show an example in which the elasto-plastic damper of the present invention is applied to a vibration damping structure.

The elasto-plastic damper A has walls B and C as shown in FIG.
Walls B are arranged at regular intervals in between, as shown by arrows, for example.
-Functions when C causes relative displacement in the opposite direction.

As shown in FIGS. 8 and 9, in this embodiment, it is composed of a pair of U-shaped members 10 and 11 and a single U-shaped member 12 connected via a guide wheel 20. Of course, U
It does not exclude an embodiment in which each pair of character members is a pair.

The open ends of the U-shaped members 10, 11 and 12 are
It is connected to 31 by bolts and nuts 60, and the extension of the bolts and nuts 60 is the wall B.
It is buried in C.

10 to 12 show examples in which the elasto-plastic damper of the present invention is applied to a seismic isolation structure.

10 and 11 show an elasto-plastic damper D according to the present invention.
・ This is an example of incorporating D into a seismic isolation structure constructed at the foundation of a building.

The elasto-plastic damper D of this embodiment is constructed as shown in FIG. That is, this embodiment has two pairs of U
One of the open ends of the adjacent U-shaped members 13 and 14 and 15 and 16 is connected to the arm member 17, respectively. The other is connected to the support members 18 and 18. Further, the supporting members 18 and 18 are connected to a substrate 19, and the substrate 19 is connected to a foundation E that supports an isolator F having a seismic isolation structure, and a connecting means provided at the tip of the arm member 17. Via the base of the superstructure of the structure. In this case, as shown in the figure, it is a preferable mode that the elastic-plastic dampers D are arranged in pairs and the tips of the arm members 17 are connected to each other.

[Advantages of the Invention] 1. By adjusting the cross-sectional shape of the U-shaped member or elasto-plastic member, the length of the rod, the number of rods, and the diameter of the guide wheel, any rigidity, proof stress, elasto-plastic rate, deformation amount, and durability can be obtained. Obtainable.

2. As a seismic isolation / vibration damping device, a mechanism that does not generate more stress than that set in advance is used to suppress an increase in input to the structure, enhance the damping effect, and quantify the damping effect. An ideal elasto-plastic damper is obtained which makes it possible to facilitate the conversion.

3. It can be applied to any vibration control system.

4. Mass production is possible because the mechanism is simple, easy to manufacture and inexpensive.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention, and FIG.
Fig. II-II line sectional view, Fig. 3 is an explanatory view of the function, Figs. 4 and 5 are plan views showing other embodiments, and Fig. 6 is a graph showing the relationship between stress and strain of an elasto-plastic body. , FIG. 7 is a schematic view showing an example of construction of a vibration damping structure, FIG. 8 is an enlarged view of the damper portion, and FIG. 9 is a central vertical plan view of the damper.
Figures and 11 are schematic diagrams showing an example of construction for a seismic isolation structure.
The figure is also an enlarged view of the damper. In the figure, each code indicates the following. 1: U-shaped member 2: Guide wheel 3: Support member 4: Wire 5: Elasto-plastic body 10: U-shaped member 11: 〃 12: 〃 13: 〃 14: 〃 15: 〃 16: U-shaped member 17: Arm member 18: Support member 19: Substrate 20: Guide wheel 30: Support member 31: 〃 60: Bolt / nut A: Elasto-plastic damper B: Wall C: Wall D: Elasto-plastic damper E: Foundation to support isolator F: Isolator

Claims (6)

[Claims] 1. An elasto-plastic body having a U-shaped portion, which is made of one or a plurality of metallic materials selected from mild steel, stainless steel, copper, lead and aluminum and / or one of polymeric materials or a composite material thereof. An elasto-plastic damper comprising a guide wheel attached to the U-shaped portion of the elasto-plastic body and having an outer diameter substantially equal to the inner diameter thereof, and a support member for fixing the legs of the elasto-plastic body. 2. The elasto-plastic damper according to claim 1, wherein the guide wheel is fixed to the support member by a wire. 3. An elastic-plastic body is formed in a loop shape having U-shaped portions at both ends, and a pair of guide wheels is provided at both ends thereof, and an axial force is directly applied to the elastic-plastic body. An elasto-plastic damper characterized by. 4. The elasto-plastic damper according to any one of claims 1 to 3, wherein the elasto-plastic body is formed of a laminated structure of two or more metals or polymer materials. 5. The elasto-plastic damper according to claim 4, wherein a rubber layer is arranged between the layers. 6. The elasto-plastic damper according to claim 1 or 2, wherein the elasto-plastic body is arranged and fixed between the support member and the arm member having a coupling means at its tip.