JPS62228729A - Vibration energy absorbing device - Google Patents

Abstract

PURPOSE:To make it possible to prevent an elastoplastic member from breaking by restraining the elastoplastic member with an elastic supporting body thereby suppressing occurrence of narrow part of bulged part. CONSTITUTION:When relative displacement in lateral direction occurs between a footing 1 and a structure 2 due to an earthquake, etc., an energy absorbing device D undergoes repeated deformation. As an elastoplastic member 5 plastically deforms here, energy consumption necessary for the plastic deformation in the elastoplastic member 5 occurs. In this case, the elastoplastic member 5, being restrained on its periphery with an elastic supporting body 8, undergoes approximately uniform shearing deformation. Accordingly, occurrence of a narrow part or bulged part is suppressed, stabilized energy absorbing function is utilized over a long period of time, and the elastoplastic member 5 is prevented from breaking.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a vibration energy absorption device used for vibration isolation or seismic isolation of structures, and in particular, relates to a vibration energy absorption device that utilizes plastic deformation of a material. The present invention relates to an improvement of a vibration energy absorbing device that absorbs vibration energy.

(Prior Art) Conventionally, in order to prevent structures from being destroyed by seismic force, various vibration energy absorbing devices have been interposed between, for example, a foundation and a structure body.

Such vibration energy absorption devices are classified based on their energy absorption mechanism: viscous type devices utilize the viscosity of a fluid or viscoelastic body, friction type devices utilize friction between materials, and vibration energy absorber devices utilize the plasticity of the materials. It is broadly divided into plastic method that utilizes deformation.

Among these, many of those that employ the plastic method utilize plastic deformation of metal materials, and have the advantage of being simpler in structure and lower in price than those of other methods. As a material constituting the elastic-plastic member directly used for energy absorption, lead, a lead-based alloy material, or an iron material is usually used. especially.

Lead-based materials have excellent plasticity and have sufficient tracking characteristics even in vibrations that involve large displacements.

By the way, conventional vibration energy absorbing devices that utilize the elastic-plastic properties of materials due to shear deformation generally do not.

It is constructed as shown in FIGS. 5, 6 and 8. That is, in the structure shown in FIG. 5, end plates 3 and 4 are fixed to the upper surface of the foundation 1 and the lower surface of the structure 2 so as to face each other, and between these end plates 3 and 4.

For example, an elastic-plastic member 5 made by processing a lead-based material into a cylindrical shape.
It has a structure with an intervening Note that each end plate 3, 4 and the elastic member 5 are joined by soldering or the like.

Also, what is shown in Figure 6.

Recesses 6 and 7 having the same diameter as the elastoplastic member 5 are formed in the end plate 3.4, and both ends of the elastoplastic member 5 are inserted or inserted into these recesses 6 and 7, whereby the elastoplastic member 5 and each End plate 3
, 4 are joined together. Furthermore, in the structure shown in FIG. 8, an elastic support 8 such as a rubber bearing for supporting the load of the structure 2 is interposed between the end plates 3 and 4, and the elastic support 8 extends in the axial direction. A through hole 9 is provided.

The elastic-plastic member 5 is accommodated within this through-hole 9. Note that the two elastic supports 8 include a rubber plate 1° and a metal plate 11.
These are alternately laminated and bonded, and each end plate is also bonded.

In these vibration energy absorption devices, when a relative displacement occurs between the foundation 1 and the structure 2 due to an earthquake, etc., the elastoplastic member 5 existing between the foundation 1 and the structure 2 When the elastic-plastic member 5 is subjected to forced displacement, an energy loss equal to the amount of work required for the plastic deformation occurs,
As a result, the vibration energy between the foundation 1 and the structure 2 is absorbed, and the vibration response of the entire structure is reduced.

However, the conventional vibration energy absorbing device configured as described above has the following problems.

That is, when the elastoplastic member 5 undergoes repeated lateral deformation due to an earthquake or the like, in the case shown in FIGS. Due to the difference in the bending and tension conditions between the two parts, a constriction occurs in the part Y near the end plates 3 and 4 and a bulge in the central part Z, as shown in FIG. 7, with a relatively small number of repetitions. do. Therefore, the resistance force required for mold deformation gradually decreases, and the energy absorption capacity decreases. Finally, the elastic-plastic member 5 breaks at the constricted portion.

There were reports that it lost its function as an energy absorbing device. On the other hand, in the case shown in FIG. 8, since one elastic-plastic member 5 is restrained by the elastic support 8, the problem described in FIG. 7 is less likely to occur. However, this structure also has the following problems. That is, when the elastic-plastic member 5 is deformed by vibration, the force F and the displacement X applied to the second elastic-plastic member 5 change as shown in FIG. As can be seen from this Kerr displacement characteristic, when the direction of motion of the elastic-plastic member 5 changes, that is, when the state changes from point A to point B, the force F applied to the elastic-plastic member 5 changes from FA to −FB.
It changes rapidly. Such a sudden change in force could excite higher-order modes in the seismic isolation system, which could have an adverse effect on the structure's equipment system.

(Problems to be Solved by the Invention) As mentioned above, simply preventing the elastic member from constricting or bulging will not provide the elastic-plastic member with good immunity from low-frequency vibration regions to high-frequency vibration regions. The seismic function cannot be activated.

Therefore, the present invention can be achieved without complicating the configuration.

To provide a vibration energy absorption device capable of sustaining the energy absorption function of an elastoplastic member used for energy absorption for a longer period of time, and capable of exhibiting its function satisfactorily over a wide frequency range. It is intended to.

[Structure of the Invention] (Means for Solving the Problems) According to the present invention, an elastic-plastic member and a buffer member are inserted in series between a structure and a support portion that supports the structure; A vibration energy absorbing device is provided that includes this buffer member and an elastic support body that is provided so as to cover the outer circumferential surface of the serial structure made of elastic-plastic members and supports the above-mentioned structure.

(Effect) When a vibration force is applied that causes relative displacement between a structure and its supporting parts, such as during an earthquake.

The elastic-plastic member absorbs vibration energy by repeatedly deforming its shape according to the amount of relative displacement. At this time, a force acts on the elastoplastic member to form a constriction at both ends and a bulge at the center. However, since the second elastic-plastic member is restrained by the elastic support, the occurrence of the above-mentioned constriction or bulge is suppressed by the elastic support. Therefore, it is possible to prevent the elastic-plastic member from breaking due to the occurrence of a constricted portion with a small number of repetitions. Further, the buffer member inserted in series with the second elastoplastic member functions to suppress sudden changes in the force applied to the elastoplastic member when the direction of movement of the second elastoplastic member is switched. Therefore, the excitation of higher-order modes can be suppressed, and as a result, the seismic isolation function can be exhibited even in the high frequency range.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example in which a vibration energy absorbing device according to an embodiment of the present invention is installed between a foundation 1 and a target structure 2. As shown in FIG. In this figure, the same parts as in FIG. 8 are indicated by the same reference numerals.

Therefore, detailed explanation of the two overlapping parts will be omitted.

This embodiment differs from conventional devices in the arrangement of the elastic-plastic member 5. That is, in this example.

A cylindrical hole 9a is provided that extends from the center of the end plate 3 to the middle of the elastic support 8 that supports the load of the structure 2, and becomes a dead end. The formed elastic-plastic member 5 is housed therein. Therefore, a portion 12 of the second elastic support 8 is interposed between the upper end of the first elastic-plastic member 5 and the end plate 4. That is, an elastic-plastic member 5 and a portion 12 of the elastic support 8 are inserted in series between the foundation 1 and the structure 2, and this series structure is eventually covered with the elastic support 8. It becomes.

In the case of this embodiment, the metal plate 11 located in the hole 9a is formed into an annular shape with an inner diameter that does not touch the outer circumferential surface of the first elastoplastic body 5.

With such a configuration, when a relative displacement occurs in the lateral direction between the foundation 1 and the structure 2- due to an earthquake or the like, the energy absorbing device repeatedly undergoes deformation as shown in FIG.

At this time, the 9 elastoplastic members 5 are plastically deformed, and the energy necessary for plastic deformation occurs within the 1 elastoplastic member 5. Therefore, the function as an energy absorption device is exhibited.

In this case, since the outer periphery of the first elastic-plastic member 5 is restrained by the first elastic support 8, it undergoes almost uniform shearing deformation. Therefore, the occurrence of the aforementioned constrictions and bulges is suppressed, and a stable energy absorption function is exhibited over a long period of time. Further, a portion 12 of the elastic support 8 is interposed between the two elastic-plastic members 5 and the end plate 4. This portion 12 is formed by laminating the rubber plates 10 and the metal plates 11 alternately and bonding them together as described above. In this way, the rubber plate 10
is inserted, when the direction of movement of the elastic-plastic member 5 is switched, even if the force applied to the elastic-plastic member 5 is about to change suddenly, it will be buffered by the rubber plate 1°. Therefore, the excitation of higher-order modes is suppressed, and as a result, the seismic isolation function can be satisfactorily exhibited even in high-frequency regions.

Note that the present invention is not limited to the above-mentioned embodiments, and can be modified in various ways. That is, as shown in FIG. 3, a plurality of other elastic-plastic members 5a are inserted in the circumferential direction so as to surround a portion 12 of the elastic support 8 existing between the two elastic-plastic members 5 and the end plate 4. You may also do so. Also, as shown in Figure 4.

A hole 13 penetrating vertically is provided in the center of the elastic support 8, and an elastic-plastic member 5 and a buffering function made of a viscoelastic material such as rubber or a viscous material such as a highly viscous liquid are provided in the hole 13. It is also possible to accommodate the members 14 in series.

In addition, the shape of the first elastoplastic member is not limited to a cylindrical shape but may be a prismatic shape, and its diameter and length are determined by the total number when this energy absorption device is actually installed, the mass of the target structure, and the rigidity of the structure. , determined by the required energy absorption and the plastic properties of the elastoplastic member used. Further, the material for forming the first elastic-plastic member is not limited to lead, and lead-based alloys and iron can also be used. Although the rigidity of the second elastic support body 8 is different from the case where the first elastic-plastic member is not inserted, the dimensions, shape, etc. of the elastic-plastic member are determined from the required amount of attenuation.

Of course, the rigidity can be set to any desired value by changing the thickness of the rubber plate or metal plate based on this.

[Effects of the Invention] As described above, according to the present invention, it is possible to provide a vibration energy absorbing device that can stably absorb vibration energy from low frequency vibrations to high frequency vibrations over a long period of time.

[Brief explanation of drawings]

wS1 is a vertical cross-sectional view of the vibration energy absorbing device according to an embodiment of the present invention when it is actually installed, and FIG. 2 is a vertical cross-sectional view of the same vibration energy absorbing device performing energy absorption operation. 3 is a longitudinal cross-sectional view of a vibration energy absorbing device according to another embodiment of the present invention, FIG. 4 is a longitudinal cross-sectional view of a vibration energy absorbing device according to yet another embodiment of the present invention, and FIG.
6 and 8 are longitudinal cross-sectional views of conventional vibration energy absorbing devices, respectively, and FIGS. 7 and 9 are diagrams for explaining the problems of the conventional device. D, Da, Db... vibration energy absorption device, 1...
Foundation, 2... Structure, 3, 4... End plate, 5.5a.
. . . Elastoplastic member, 8 . . . Elastic support body, 10 . Applicant's Representative Patent Attorney Takehiko Suzue Figure 1 Figure 2 Figure 3 L Figure 4 Figure 5 vK6 Figure 7 Figure 8 Figure 911

Claims (4)

[Claims] (1) An elastic-plastic member and a buffer member inserted in series between a structure and a support part that supports the structure, and a structure that covers the outer circumferential surface of the serial structure consisting of the buffer member and the elastic-plastic member. 1. A vibration energy absorbing device comprising: an elastic support provided at the structure to support the load of the structure. (2) The vibration energy absorbing device according to claim 1, wherein the elastic-plastic member is made of one selected from lead, a lead-based alloy, and iron. (3) The vibration energy absorbing device according to claim 1, wherein the buffer member is made of the same material as the elastic support and is formed integrally with the elastic support. (4) The vibration energy absorbing device according to claim 1, wherein the buffer member is made of one selected from a viscoelastic material and a viscous material.