JP2006242239A - Energy absorbing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an energy absorbing device for reducing vibration energy transmitted to a building or a civil structure in earthquake, having stable energy absorbing performance and high repeating durability and being easy and inexpensive to manufacture. <P>SOLUTION: The energy absorbing device comprises a hollow portion h provided vertically passing through a laminate 3 which consists of a plurality of hard plates 1 such as steel plates and a plurality of elastic bodies 2 such as rubbers alternately laminated in the vertical direction, and an energy absorber 4 stored in the hollow portion h for absorbing vibration energy of earthquake or the like. The energy absorber is formed of a material having a lower yielding point at each vertical end than at the center. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an energy absorbing device for reducing vibration energy transmitted to a building, a civil engineering structure, a precision instrument, or the like when an earthquake occurs. More specifically, the present invention relates to an energy absorbing device in which an energy absorber that absorbs vibration energy such as earthquake is provided in a laminate in which a plurality of hard plates such as steel plates and elastic bodies such as rubber are alternately laminated in the vertical direction. Is.

  Conventionally, for example, the following Patent Documents 1 and 2 have been proposed as energy absorbers that reduce vibration energy transmitted to buildings, civil engineering structures, and the like when an earthquake occurs. FIG. 10 shows an example, and an energy absorbing device A of the present example includes a pair of upper and lower laminates 3 in which a plurality of hard plates 1 such as steel plates and elastic bodies 2 such as rubber are alternately laminated in the vertical direction. Lead that absorbs vibration energy such as earthquakes in a hollow portion (through hole) h that is arranged between the substrates 5 and 5 and is formed in the center portion of both the substrates 5 and 5 and the laminated body 3 in the vertical direction. It is the structure which accommodated and arrange | positioned the energy absorber 4 which consists of these elastic-plastic bodies.

  As shown in FIG. 10, mounting plates 6 are integrally attached to the upper and lower ends of the laminate 3 and the energy absorber 4 via a substrate 5, respectively, and the mounting plates 6 are constructed with bolts or the like (not shown). It is a structure to be attached to an object or a civil engineering structure. Specifically, for example, in a building such as a building as shown in FIG. 11, between the upper structure B such as the building and the lower structure C such as the base, and in FIG. In a civil structure such as a bridge as shown, one or a plurality of the energy absorbing devices A are arranged between an upper structure B such as a bridge girder and a lower structure C such as a pier, A bolt or the like is inserted into the mounting hole 6a formed in the upper and lower mounting plates 6 of each energy absorbing device A and is mounted on the structures B and C.

  The energy absorbing device A arranged between the upper and lower structures B and C as described above is designed to reduce seismic energy by deforming in the horizontal direction when an earthquake occurs while stably supporting a building or the like. It functions as both a seismic isolation isolator and a seismic isolation damper. As a result, the installation space can be reduced and the workability can be improved as compared with the case where the isolator and the damper are separately arranged.

  By the way, in the said patent document 1, when manufacturing the above energy absorption apparatuses, applying the hydrostatic pressure equivalent to or more than the shear yield stress to the energy absorber which consists of an elastic-plastic body is proposed. ing. Moreover, in patent document 2, when manufacturing the above energy absorption apparatus, the volume in the hollow part h is larger than 1.0 with respect to the volume of the energy absorber 4 which consists of an elastic-plastic body from 1.05. It has been proposed to reduce slippage between the energy absorber 4 and the hollow portion h by reducing the size.

  For example, when the energy absorber 4 is accommodated in the hollow portion h formed in the laminate 3, the energy absorber 4 is brought into close contact with the inner surface of the hollow portion h so that there is no gap between them. However, there is a problem that the energy absorber 4 does not plastically deform as ideally and adversely affects the energy absorption capacity and the repeated durability. Moreover, by applying an application equal to or greater than the yield point of the elastoplastic body, the surface pressure between the elastoplastic body and the laminated rubber is high, and the resistance force between the two becomes large. As a result, the elastoplastic body loses the resistance force, and the elastoplastic body may roll up or crack in the worst case.

  The mechanism will be described with reference to FIG. 13. In the energy absorbing device, the outer peripheral surface of the energy absorbing body 4 is initially hollow in the laminate 3 by hydrostatic pressure applied to the energy absorbing body 4 at the time of manufacture. It is in a state of being in close contact with the inner surface of the portion h. In this state, when the upper substrate 5 is deformed so that the upper substrate 5 is relatively displaced to the right in the figure as a result of vibration due to an earthquake or the like, the internal energy absorber 4 is also moved accordingly. Plastic deformation as shown. Then, the energy absorber 4 is displaced so as to be stretched as a whole, and its diameter, particularly the diameter of the central portion, is deformed so as to be thin as shown in FIG.

  Next, when the upper substrate 5 is deformed (returned deformed) from the state of FIG. 13C in the direction returning to the original position on the left side in the drawing, the energy absorber 4 is positioned at both the upper and lower ends. While undergoing compression by 5, the deformation is performed such that the diameter swells. In particular, both ends of the energy absorber 4 close to the substrate 5 receive more compressive force and expand more. On the other hand, since the compression from the substrate is not transmitted so much in the vicinity of the central portion of the energy absorber 4 in the vertical direction, there is little change in the diameter.

  As described above, whenever the energy absorbing device moves in the horizontal direction due to vibration caused by an earthquake or the like, different deformation and flow occur near the upper and lower ends and near the center of the energy absorber 4. As a result, as shown in FIG. 13 (d), the energy absorber 4 becomes irregular and non-homogeneous in the vicinity of the central portion and both end portions of the energy absorber 4, and shear fracture occurs near the boundary. Peeling or cracking, peeling from the inner surface of the energy absorber 4 and the hollow portion due to a difference in diameter between the center portion and both ends, or a gap is generated at the corner of the energy absorber 4. As a result, there are problems such as unstable energy absorption performance and reduced durability.

Japanese Patent No. 3360828 JP-A-11-29986

  The present invention has been proposed in view of the above problems, and an object thereof is to provide an energy absorption device that has stable energy absorption performance, high repetition durability, and that can be easily and inexpensively manufactured. To do.

  In order to achieve the above object, an energy absorbing device according to the present invention has the following configuration. In other words, a laminated body made by alternately laminating a hard plate such as a steel plate and an elastic body such as rubber in the vertical direction has a hollow portion penetrating in the vertical direction, and absorbs vibration energy such as earthquakes in the hollow portion. In the energy absorbing device in which the energy absorber to be accommodated is arranged, both end portions in the vertical direction of the energy absorber are formed of a material having a lower yield point than the central portion.

  As described above, the upper and lower ends of the energy absorber are made of a material having a yield point lower than that of the center portion, so that the displacement and deformation of the energy absorber are hindered when absorbing vibration energy such as earthquakes. Therefore, it is possible to satisfactorily absorb vibration due to an earthquake or the like. In addition, the energy absorption device having high energy absorption performance, its stability, and high repetition durability can be easily and inexpensively manufactured by the extremely simple configuration as described above.

  Hereinafter, the present invention will be specifically described based on embodiments shown in the drawings. FIG. 1 is a perspective view showing an embodiment of an energy absorbing device according to the present invention, and FIG. 2 is a longitudinal sectional view thereof. Members having the same functions as those in the conventional example will be described with the same reference numerals.

  The energy absorbing device A of the present embodiment is a laminated body in which a hard plate 1 such as a steel plate and an elastic body 2 such as rubber are alternately laminated in the vertical direction and integrated with an adhesive or the like as in the conventional example. 3 is arranged between a pair of upper and lower substrates 5 and 5, and vibration energy such as an earthquake is placed in a hollow portion (through hole) h penetrating in the vertical direction formed in the central portion of both the substrates 5 and 5 and the laminate 3. It is the structure which accommodated and arrange | positioned the energy absorber 4 which consists of elastic-plastic bodies, such as a tin to absorb.

  In the present invention, both end portions 4b in the vertical direction of the energy absorber 4 are formed of a material having a lower yield point than the central portion 4a. In the present embodiment, the central portion 4a of the energy absorber 4 is formed of tin. Both ends 4b and 4b are made of lead having a yield point lower than that of tin, and their materials are appropriate. The vertical length (height) formed of the material having a low yield point at each of the end portions 4b and 4b is preferably 20% or less of the vertical length of the entire energy absorber. This is because even if it is larger than that, the effects described later are few. Examples of materials other than tin include bismuth, aluminum, copper, antimony, lead, silver, zinc, iron, and indium.

  Moreover, although the carbon steel plate was used in this embodiment as the hard plate 1, a stainless steel plate, another metal plate, a hard synthetic resin plate, etc. can also be used. In the present embodiment, natural rubber is used as the elastic body 2, but synthetic rubber, soft synthetic resin, or the like may be used. In the longitudinal sectional view of FIG. 2, the hatching of the hard plate 1, the elastic body 2, and the energy absorbing body 4 (hatched lines indicating the cross section) is omitted to avoid complication. The same applies to other longitudinal sectional views and explanatory views to be described later.

  A mounting plate 6 is integrally attached to the upper and lower ends of the laminate 3 and the energy absorber 4 configured as described above with bolts 7 or the like via the substrate 5 as in the conventional example. An attachment hole 6 a is formed in 6. As in the conventional example of FIGS. 8 and 9, one or a plurality of the energy absorbing devices A are provided between an upper structure B such as a building or a structure and a lower structure C such as a base. The bolts 8 and the like are inserted into the mounting holes 6a provided in the energy absorbing devices A and attached to the structures B and C.

  When configured as described above, the following effects can be obtained. That is, when the laminate 3 is deformed when absorbing vibration energy, the internal energy absorber 4 is stretched in the vertical direction as described above, and rotates in the vicinity of the end 4b. A gap is generated in the boundary portion between the end portion 4b and the substrate 5 which is forced between the substrate 5 and the substrate 5 due to the forward deformation and the return deformation. As a result, in the history, the horizontal rigidity is reduced accordingly. On the other hand, when the upper and lower end portions 4b of the energy absorber 4 are formed of a material having a lower yield point than the central portion 4a as described above, the rotational motion generated in the vicinity of the end portion 4b is reduced and the energy absorber 4 rotates slightly. However, the generation of a gap with the substrate 5 is reduced as much as possible. Therefore, the horizontal rigidity is also maintained, and as a result, it is resistant to repeated vibrations and can maintain a stable energy absorption capability.

  FIG. 3 shows a schematic configuration when absorbing vibrations such as earthquakes using the energy absorbing device of the above embodiment, and it is initially accommodated in the hollow portion h of the laminate 3 as shown in FIG. The energy absorber 4 is in a state where its outer peripheral surface is almost in close contact with the inner surface of the hollow portion h. In this state, when the upper substrate 5 is deformed so that the upper substrate 5 is relatively displaced to the right in the figure as a result of vibration due to an earthquake or the like, the internal energy absorber 4 is also moved accordingly. Plastic deformation as shown. At this time, since the yield force of the energy absorber 4 is greater than the surface pressure generated between the energy absorber 4 and the inner surface of the hollow portion h, the energy absorber 4 is deformed or displaced almost freely. The diameter of the central portion in the vertical direction of the energy absorber 4 is not reduced as in the prior art.

  Next, when the upper substrate 5 is deformed from the state of FIG. 3B in the direction of returning to the original position on the left side (return deformation) as shown in FIG. In addition, even when a compressive force is applied from the substrate 5 located at both upper and lower ends, the energy absorber 4 is not restricted by the surface pressure generated between the inner surface of the hollow portion h and the energy absorber 4 is restricted. Since the above-mentioned compressive force acts on the entire length in the longitudinal direction, the diameter of only the both end portions does not swell as described above. Further, unlike the prior art, there is no flow of energy absorbers 4 at the corners of the both end portions, or the flow of rotating in a complicated manner.

  Therefore, the energy absorbing device of the above-described embodiment according to the present invention has different deformation and flow in the vicinity of the upper and lower end portions and the central portion of the energy absorber 4 each time it moves in the horizontal direction due to vibration caused by an earthquake or the like. The entire energy absorber 4 is deformed without any deviation, and even if this is repeated, the initial state is maintained as shown in FIG. Therefore, there is no occurrence of irregularity or inhomogeneity of the crystalline structure of the energy absorber 4 as in the prior art, and cracking, peeling, or generation of gaps, and the like. The vibration absorbing performance can be maintained.

  In the above embodiment, the hollow portion h is provided so as to penetrate both the laminate 3 and the upper and lower substrates 5, 5. However, the upper and lower substrates 5, 5 are provided with the hollow portion h as shown in FIG. You may provide the hollow part h only in the laminated body 3 without providing. Even when the energy absorber 4 is accommodated and disposed in the hollow portion h, and both end portions 4b in the vertical direction of the energy absorber 4 are formed of a material having a yield point lower than that of the central portion 4a, the same effect as described above can be obtained. can get.

  In addition, the energy absorber 4 of the same material may be accommodated in the hollow portion h provided only in the laminate 3 as shown in FIG. 5, and the laminate 3 and the upper and lower substrates 5 as shown in FIG. -An energy absorber 4 of the same material length is accommodated in a hollow portion h provided so as to penetrate both of the five, and an antifriction material is provided between the energy absorber 4 and the substrate 5 as necessary. 10 may be interposed. The antifriction material 10 is, for example, a solid or powdery lubricant such as Teflon (registered trademark) or molybdenum, or a liquid lubricant such as grease or oil, or the above-described solid or powdery lubricant and liquid. Both lubricants can be used in combination.

  When the antifriction material 10 is interposed between the energy absorber 4 and the substrate 5 as described above, a gap due to deformation accompanying further rotation near the end of the energy absorber 4 is less likely to occur when absorbing vibration energy. As a result, it is possible to continue a stable energy absorption capability that is resistant to repeated vibrations.

  Next, as a specific example of the present invention, an energy absorbing device as shown in FIG. 5 was actually fabricated and subjected to a vibration test. The results are shown in FIGS. In addition, the dimension and material of each part of the energy absorber produced in the present Example are as follows. First, the height of the laminated body 3 in FIG. 5 is 250 mm including the upper and lower substrates 5, the outer diameter is φ500 mm, the height of the energy absorber 4 as the core is 218 mm, the outer diameter is φ100 mm, and the energy absorption The material of the body 4 was an alloy obtained by adding 0.3% bismuth to 99% purity tin and having a yield point of 20 MPa. On the other hand, as a comparative example with respect to the above example, an energy absorbing device similar to the above example was used except that the upper and lower end portions of the energy absorber 4 extended into the upper and lower substrates 5 and the height was 250 mm.

  The vibration test was performed with a test deformation speed of 5 mm / s and a test deformation amount (horizontal displacement amount relative to the total thickness of the elastic body 2) of 250% deformation (horizontal displacement amount of about 310 mm). FIG. 7 shows a displacement history curve of the first cycle in the above-described example and comparative example. At this point, there is not much difference in the history loop shape in both the example and the comparative example. However, in FIG. 8 where the history of the 10th cycle is taken under the same excitation condition, it can be seen that the energy absorption amount, which is the area in the history loop, is lower in the comparative example than in the example. Further, FIG. 9 shows the measurement of the rate of decrease of the energy absorption amount for each cycle with the initial energy absorption amount being 1.0. It can be seen that it is excellent in durability repeatedly by about 1 less.

  As described above, the energy absorbing device according to the present invention can absorb vibrations due to earthquakes and the like satisfactorily by forming both ends in the vertical direction of the energy absorber with a material having a lower yield point than the central portion. However, with an extremely simple configuration, it is possible to easily and inexpensively manufacture an energy absorbing device having high energy absorption performance and stability, and high durability. As a result, the degree of freedom in designing and selecting the energy absorbing device as described above can be increased, and industrial applicability can be increased.

The perspective view which shows one Embodiment of the energy absorption apparatus by this invention. The longitudinal cross-sectional view of the energy absorber of the said embodiment. Schematic structure explanatory drawing which shows the operation state of the said energy absorption apparatus. The longitudinal cross-sectional view which shows other embodiment of the energy absorption apparatus by this invention. The longitudinal cross-sectional view which shows other embodiment of the energy absorption apparatus by this invention. The longitudinal cross-sectional view which shows other embodiment of the energy absorption apparatus by this invention. The displacement history curve figure of the Example based on this invention, and a comparative example. The displacement history curve figure of the Example based on this invention, and a comparative example. The energy absorption amount change measurement figure of the Example based on this invention, and a comparative example. The longitudinal cross-sectional view which shows an example of the conventional energy absorption apparatus. Explanatory drawing of the example which constructed the said conventional energy absorption apparatus in the building. Explanatory drawing of the example which constructed the said conventional energy absorption apparatus to the civil engineering structure. Schematic structure explanatory drawing which shows the operation state of the said conventional energy absorption apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hard board 2 Elastic body 3 Laminated body 4 Energy absorber 5 Board | substrate 6 Mounting plate 7, 8 Bolt A Energy absorber B Upper structure C Lower structure h Hollow part

Claims (5)

Energy that absorbs vibration energy such as earthquakes in a hollow part that penetrates in the vertical direction in a laminated body in which multiple hard plates such as steel plates and elastic bodies such as rubber are alternately laminated in the vertical direction In the energy absorption device that houses and arranges the absorber,
An energy absorbing device, wherein both ends of the energy absorber in the vertical direction are made of a material having a lower yield point than the central portion.   The energy absorbing device according to claim 1, wherein the length of both ends in the vertical direction formed of the material having a low yield point is 20% or less of the length in the vertical direction of the entire energy absorber. Energy that absorbs vibration energy such as earthquakes in a hollow part that penetrates in the vertical direction in a laminated body in which multiple hard plates such as steel plates and elastic bodies such as rubber are alternately laminated in the vertical direction In the energy absorption device that houses and arranges the absorber,
A substrate is provided at each of both end portions of the laminate in the stacking direction, and both end portions in the vertical direction of the energy absorber are not extended and provided in each substrate.   The energy absorbing device according to claim 3, wherein an antifriction material is interposed between both ends of the energy absorber and the substrate. As the antifriction material, a solid or powdery lubricant such as Teflon or molybdenum, or a liquid lubricant such as grease or oil, or both of the above solid or powdery lubricant and liquid lubricant are used in combination. The energy absorbing device according to claim 4.

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