JPH03183876A - Elastic and plastic damper - Google Patents

Abstract

PURPOSE:To promote the effect of vibration control by forming an elastic and plastic body having a U-shaped part, a guide wheel mounted on the U-shaped part of the elastic and plastic body and bearing members to which a leg section of the elastic and plastic body is fixed. CONSTITUTION:An elastic and plastic damper is constituted of U-shaped members 1 to function as an elastic and plastic body, a guide wheel 2 with which a U-shaped part is interlocked, bearing members 3 and wires 4 to bear the wheel 2 on the bearing members 3. After that, when a relative variation in the bearing members 3 occurs in the direction of the arrow, the members 1 move to a part to generate strain or a part to release strain as the rotation of the wheel 2, and the whole form is changed from U to J. Then, curvature is constrained by the wheel 2, and the concentration of strain to a specific section is avoided. According to the constitution, the effect of vibration control against the large external disturbance can be also promoted.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a damper used in the seismic isolation or restraint structure of buildings, and more specifically, to a damper that absorbs energy such as an earthquake through deformation. This paper relates to elasto-plastic dampers that utilize the characteristics of elasto-plastic materials that deform elastically under small deformations and plastically under large deformations.

[Prior Art] Conventional elastoplastic dampers often use bending, shearing, and torsional deformation of metal materials such as steel and lead, either singly or in combination.

When a metal material is deformed by bending, shearing, or torsion, if the strain exceeds a certain level, the material will break. In elastoplastic dampers with conventional mechanisms, as the amount of deformation of the damper increases, the strain in the plastically deformed part increases.
Moreover, since the occurrence of plastic strain and its repetition are concentrated in a specific cross section, the practical limit value of the plastic modulus of the restoring force characteristic as a damper is about 5 to 10. In order to increase the deformation ability, it is necessary to increase the amount of elastic deformation, but in this case, the damper cannot function as a damper against the effects of small disturbances. Conversely, in order to function as a damper against the action of small disturbances, it is necessary to set the elastic limit small, and in that case, when large disturbances act, geometric nonlinearity, distortion effects, etc. It is strongly affected by factors that are difficult to quantify, resulting in poor deformability and an extremely high possibility of breakage.

[To be solved by the invention] The present invention was created to improve the problem that existing elasto-plastic damper mechanisms cannot maintain stable hysteresis characteristics against repeated deformation at large plasticity ratios. Specifically, it was conducted with the following objectives:

A1 To prevent bending strain from concentrating on a specific part of an elastoplastic material, and also to prevent large bending strain that would directly affect fracture from occurring over its entire cross section.

B, between small and large plasticity rates.

Always draw a stable hysteresis loop so that there is no major change in proof stress or rigidity even if the amount of deformation or number of repetitions increases.

C9 To suppress the influence of geometric nonlinearity and create a mechanism that is easy to quantify analytically.

D. To prevent the restoring force characteristics from deteriorating brittlely.

[Means for Solving the Problems] The elasto-plastic damper of the present invention includes an elasto-plastic body made of a relatively highly ductile metal material and/or polymeric material, or a composite material thereof, and having a U-shaped portion; consisting of a guide wheel attached to the U-shaped portion of the elastoplastic body and having an outer diameter approximately equal to the inner diameter thereof, and a support member that fixes the legs of the elastoplastic body; the guide wheel is fixed to the support member by a wire; The elastoplastic body is formed into a loop shape with a U-shaped portion at both ends, and a pair of guide wheels are provided at both ends.The elastoplastic body is made of two or more metals or polymeric materials. by aF
A rubber layer is arranged between the layers, and an elastoplastic body is arranged and fixed between the support member and the arm member having a coupling means at the tip. , are each characterized by

[Example] Next, the present invention will be described in detail according to an example shown in the accompanying drawings.

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

The inner diameter of the U-shaped portion of the U-shaped member 1 is the same as that of the guide wheel 2.
The U-shaped member 1 as an elastoplastic body, which is set to be approximately equal to the outer diameter of Form using. When using materials such as polymer materials and lead that are particularly soft and may elongate as bending deformation increases and the number of repetitions thereof increases, bending rigidity is low and tensile rigidity is low, such as wire. It is preferable that the reinforcement be made of a material with high resistance.

Note that there are no limitations on the cross-sectional shape of the U-shaped member 1 and the number of U-shaped members arranged.

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 U-shaped member 1 changes into an unstable shape as shown by the 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 opposite to each other, and a guide wheel 2 is inserted between them. In this case, if a force is applied as shown by the arrow, the individual U-shaped members l will be restrained from deforming as shown by the broken lines in Figure 3, and the whole will change from a U-shape to a J-shape in a stable shape. Show change.

When a relative displacement occurs in the support member 3 in the direction of the arrow, U
In the shape member L, as the guide wheel 2 rotates, the part where the distortion occurs or the part where the distortion is released moves, and the overall shape changes from a U-shape to a J-shape, but the curvature is restrained by the guide wheel 2. Therefore, concentration of strain on a specific cross section can be avoided. If the curvature of the guide wheel 2 is used within the range where the strain of the elastoplastic material is on the yield shelf as shown in Figures 5 and 6, it will not only be easy to estimate the proof stress of the damper. , extremely stable energy absorption performance can be obtained without being influenced by material strain effects.Moreover, this hysteresis loop has a significant characteristic in that the yield stiffness is almost equal to zero, and it is close to a completely elastoplastic shape.

As the number of repeated loads on the damper increases, U
It is foreseen that some parts of the character-shaped member 1 will break. In order to prevent the guide wheel 2 from coming off and brittlely destroying the damper mechanism in such a case, and to ensure that it can continue to exhibit stable hysteresis characteristics, the guide wheel 2 is pre-wired with, for example, four wires. 4 is preferably supported on the support member 3.

When assembling the damper, the supporting member 3 and the U-shaped member 1. If the U-shaped member 1 and the guide wheel 2 are attached so that there is no gap between them, although the proof stress of the damper remains the same, it is possible to obtain hysteresis characteristics with higher initial rigidity.

FIG. 4 shows a second embodiment of the invention, in which two guide wheels 2 are mounted at a constant distance.
・A loop-shaped elastoplastic body 5 made of the same material as the U-shaped member l shown in Figs. 1 and 2 is attached around 2, and an axial force is applied directly to this member. By adding this, it is possible to obtain the same history characteristics as in the first embodiment.

As shown in FIG. 5, the U-shaped member l (elastoplastic body 5) is
It is also preferable to have a laminated structure, and it is also preferable to have a composite structure in which each layer is made of a different material.Also, although not shown, a rubber layer is arranged between the calendar and the layer. It is also preferable to configure it so that it can accommodate slight dimensional changes in the width direction.

7 to 9 show examples in which the elastoplastic damper of the present invention is applied to a restraining structure.

As shown in FIG. 7, the elastic-plastic dampers A are arranged at regular intervals between the walls B-C, and for example, as shown by the arrows, the elasto-plastic dampers A
It works when C causes a relative shift in the opposite direction.

As shown in FIGS. 8 and 9, this embodiment 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. As shown in FIGS. Of course, this does not preclude an embodiment in which each U-shaped member is a pair.

The open end of each U-shaped member 10, 11, 12 is connected to the support member 30, 31 by a bolt/nut 60, the extension of which is inserted into the wall B-C like a stud bolt. Buried.

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

FIGS. 1O and 11 show an example in which the 'i1m plastic damper DD according to the present invention is incorporated into a seismic isolation structure constructed in the foundation of a building.

The elastoplastic damper D of this embodiment is constructed as shown in FIG. That is, in this embodiment, two pairs of U
It is composed of a combination of U-shaped members 13, 14, 15, and 16, and one of the open ends of adjacent U-shaped members 13 and 14 and 15 and 16 is connected to an arm member 17, respectively. The other end is connected to support members 18, 18. Further, the supporting members 18 are connected to a substrate 19, which is connected to a foundation E that supports the isolator of the seismic isolation structure, and a connecting means provided at the tip of the arm member 17. It is connected to the foundation of the superstructure of the building via. In this case, as shown in the figure, elastoplastic dampers D are arranged in pairs and their arm members 17
In a preferred embodiment, the tips of the two are joined together.

[Effects of the invention] 1. Any rigidity, yield strength, elasto-plastic modulus, deformation amount, and durability can be achieved by changing the cross-sectional shape of the U-shaped member or elasto-plastic member, the length and number of rods, and the diameter of the guide wheel to m sections. can be obtained.

2. As a seismic isolation and restraint device, by using a mechanism that does not generate stress greater than the preset value in the device, it is possible to suppress the increase in input to the structure, increase the vibration damping effect, and quantify the vibration damping effect. An ideal elastoplastic damper can be obtained that allows for easy fabrication.

3. Applicable to all vibration damping construction systems.

4. The mechanism is simple, easy to manufacture, and inexpensive, allowing for mass production.

[Brief explanation of drawings]

FIG. 1 is a plan view showing one embodiment of the present invention, and FIG. 2 is a plan view showing one embodiment of the present invention.
Figure ■-11 line sectional view, Figure 3 is an explanatory diagram of functions, Figures 4 and 5 are plan views showing other embodiments, Figure 6 is a graph showing the relationship between stress and strain of an elastoplastic body. , Fig. 7 is a schematic diagram showing an example of construction on a restraining structure, Fig. 8 is an enlarged view of a part of the damper, Fig. 9 is a central longitudinal sectional plan view of the damper, and Figs. 10 and 11 are seismic isolation. FIG. 12, which is a schematic diagram showing an example of construction on a structure, is an enlarged view of the damper. In the figure, each symbol indicates the following. l: U-shaped member 2 guide wheel 3: supporting member 4: wire 5: elastic-plastic body 10: U-shaped member 1 l no 12: no 1 13: J no 14: ll 15: H! 6: U-shaped member 17: Arm member 18: Supporting member 19: Substrate 20 Ni Guide wheel 30: Supporting member 31: ll 60: Bolt/Nut A: Sensitive damper B: Wall C: Wall 2 Elastoplastic damper E Foundation supporting the isolator

Claims (1)

[Claims] 1. An elastoplastic body made of a relatively highly ductile metal material and/or polymeric material or a composite material thereof, and having a U-shaped portion; attached,
a guide wheel having an outer diameter approximately equal to its inner diameter;
An elasto-plastic damper consisting of a support member that fixes the legs of an elasto-plastic body. 2. The elastic-plastic damper according to claim 1, wherein the guide wheel is fixed to the support member by a wire. 3. An elasto-plastic damper in which the elasto-plastic body is formed into a loop shape with U-shaped portions at both ends, and a pair of guide wheels are provided at both ends of the loop. 4. Claims 1 to 4, wherein the elastoplastic body is formed into a laminated structure of two or more metals or polymeric materials.
3. The elastoplastic damper according to any one of 3. 5. The elastic-plastic damper according to claim 4, characterized in that a rubber layer is disposed between the layers. 6. The elastoplastic damper according to any one of claims 1 to 5, wherein the elastoplastic body is arranged and fixed between the support member and the arm member having a coupling means at its tip.