JPS61176776A - Cyclic shearing energy absorbing apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an energy absorption device for use in conjunction with a large structure to reduce externally induced effects on the structure.

Periodic shear energy absorption devices are known that absorb kinetic energy by utilizing periodic plastic deformation that exceeds the elastic limit of a specific material. Such absorbers are typically placed between a support member and a foundation member of a building, or between two structural support members, to convert a portion of the kinetic energy into heat within the absorber to reduce earthquake or storm damage. Reduces the motion exerted on the structure by externally induced forces such as Robln
US Patent No. 4,117, dated October 3, 1978, to Son.
, No. 637, ``Periodic Shear Energy Absorber'' discloses several geometric configurations of basic periodic shear energy absorbers.

This basic device includes a pair of spaced apart connecting members, one member of which is a plate designed to connect to individual structural members. When this is used in a built environment, for example, one connecting member is shaped to attach to a support pile, and another connecting member is shaped to be attached to a support column, beam, or the like. Between these two connecting members a solid material, typically a block of lead, which can be periodically plastically deformed is placed, which is used as an energy absorbing material to absorb this energy. The absorbent mass is further recessed with an additional resilient pad structure, which provides a resilient vertical support between the two connecting members. This is usually a punditch structure consisting of alternating layers of elastic material, such as gum, and layers of stiffener, such as steel, aluminum, etc.

During use, when an externally induced force causes a relative lateral movement between the two connecting members and the solid energy-absorbing mass undergoes periodic movement beyond its elastic limit, the energy loss occurs. A portion of it is converted into heat, and this lump becomes deformed and accumulates the energy of the residue. The energy stored in the deformation acts as a driving force that tends to return the material to its original mechanical properties. As a result, the energy transferred to or passing through the structure does not act to destroy the structure, but is converted into heat. The safety factor of structures incorporating such absorbers is greater than that of structural members that rely on ductile behavior to dissipate energy.
This is because ductile structural members can be damaged by severe earthquakes and are difficult to repair or replace, and rubber cushions act like elastic springs, dissipating small amounts of externally applied energy. This is because it is only a matter of letting people know.

Although the above-described periodic energy absorbing device has been found to work well in many application cases, in some cases the energy absorbing mass deteriorates prematurely after observing a small number of oscillations.

This is because the absorbent mass, without a surrounding confinement member, is free to stretch in a direction perpendicular to the applied deformation, reducing its effectiveness as an energy absorber. Even in applications surrounded by elastic supports/quads with energy-absorbing lead core VI-Fundwitch structures, the effectiveness of the confinement member depends on the vertical loading, the stiffness of the elastic body, and the thickness of the individual layers of the elastic body. Dependent. Hardness coefficient 50-55
, and for an elastic body with a layer thickness of 1.273 (0.5 inches), in particular, the shear strain is 0.5 and the vertical load is less than 0.4 times the rated load of the support t4. When this happens, the performance of the lead core material deteriorates.

It is an object of the present invention to provide an improved cyclic shear energy absorption device that substantially reduces performance degradation;
Or at least provide the public with a useful choice.

[Summary of the invention]

The present invention relates to an improved cyclic shear energy absorber having a longer service life than known energy absorbers;
Provides basic equipment energy absorption benefits.

The present invention includes, in its broadest scope, all periodic shear energy absorption devices for absorbing energy due to induced motion between two members, which energy absorption devices include support columns and support piles for buildings. like 1st
and first and second coupling means respectively adapted to be coupled to a second member; and a plastically cyclically deformable energy absorbing means coupled between the first and second said coupling means. , restraining means arranged around the energy absorbing means in the region between the first and second coupling means. The restraining means has a flexible wall that confines the energy absorbing means during induced motion between the two members, causing the energy absorbing means to physically deform in a predetermined manner. The flexible wall has some elasticity and therefore absorbs the vertical component of the force, but remains confined to the energy absorbing means. In a preferred embodiment of the invention, the restraining means comprises a flat member generally helically wrapped around the outer surface of the energy absorbing means, and the flexible wall surface is created by layers of individual wrapped members. At least some of the layers are separated from adjacent layers by elastic materials.

In another preferred embodiment, the restraining means comprises a series of flat members surrounding the outer surface of the energy absorbing material, at least some of which are separated from adjacent members by an elastic material. Preferably, the restraining means is surrounded by a resilient support disposed between the first and second connecting means, the resilient support comprising alternating resilient materials such as rubber and stiffeners such as steel, aluminum or fiberglass. It is preferable to include it as a layer.

A preferred geometry is such that the energy absorbing means is a cylindrical core recessed between opposing surfaces of the first and second connecting means, the restraint means is a helically wound flat helix, and the resilient support is a helically wound flat helix. A rectangular or square layer of rubber and steel with a cylindrical opening in the center for receiving the restraining means and core material.

The present invention provides a method for assembling the elastic support and preferably inserting the restraint means to restrain the energy-absorbing core material with the aid of a guiding inset, such as a mandrel, having a diameter substantially equal to the desired inner diameter of the restraint means. In order to enter the means, the core material is either pressed into a hole within the restraint means or cast into the restraint means.

In one embodiment, the absorbent core contains two end plates and is combined by vulcanization or coupling.
Drill a hole in one end plate aligned with the cylindrical energy absorbing core and thread the hole. The end cap is also threaded and screwed into the hole to compress the core material.

During use, when the two coupling means are vibrated and displaced laterally, the elastic support, the restraining means and the energy absorbing core follow this movement, the restraining means causes the energy absorbing core to plastically deform and at the same time the core material Surround the heartwood to protect it from excessive mechanical wear.

A thorough understanding of the nature and advantages of the invention may be realized by reference to the following detailed description taken in conjunction with the accompanying drawings.

[Description of preferred embodiments]

In the drawings, FIG. 1 is a perspective view of a preferred embodiment of the invention. As shown, the energy absorbing device has a central cylindrical energy absorbing core 2, a core 2t-surrounding flexible restraining means 3, an elastic support 4 and top and bottom connecting plates 7,8.

2 and 9, the resilient support pad 4 is preferably made of a resilient material 5 of a resilient material such as natural or synthetic comb 9 and preferably of steel, aluminum, fiberglass or other suitable stiffening material. It has a sandwich structure in which stiffener plates 6 made from aluminum are alternately laminated. The resilient support 4 acts as a support knot to transmit vertical loads through the device, and the support 4 is normally placed between the bottom of a vertical support beam engaged or attached to the bottom plate 8.

The individual layers 5, 6 are typically adhered to each other to form a monolithic structure, most commonly by vulcanization.

Preferably, the restraining means 3 is a spirally wound cylindrical structure made from a suitable IJ material having a rectangular cross section. Suitable materials include spring steel, mild steel, aluminum strip, and other materials that can be wound into the spiral shape shown.

The energy absorbing core material 2 is preferably made of high purity lead formed into a cylindrical shape as shown. The term "high purity lead" means lead with a purity of 99.91. In many applications, slightly less pure lead, about 98% lead, can be used.

Other suitable materials are those described in US Pat. No. 4,117,637 and equivalent materials having similar cyclic plastic deformation properties.

The apparatus shown in Figures 1 and 2 is preferably manufactured as follows. The resilient support 4 is first formed from individual members square as shown or of any other suitable geometry, with the central opening aligned with the center of the support 4 to form a complete cylindrical opening. Thereafter, the restraining material 3 is inserted into this opening. This is preferably done with the aid of a cylindrical mandrel. The energy-absorbing core 2 is then pressed inside the restraint 3, and then the top and bottom plates are placed as shown. For best results, use high-purity lead as the energy-absorbing core 2. First, the cylindrical absorbent core material 2 is cast, and then it is pressed and fitted into the restraint material 3.The size of the cylindrical absorbent core material 2 is slightly smaller than the inner diameter of the restraint material 3, and the absorbent core material 2 is pressed into the restraint material 3. Core material 2t - Snap into the inner surface of the restraining material 3.Furthermore, the cylindrical absorbent material 2 needs to be slightly longer than the axial length of the assembled device. When casting the energy absorbing core 2 (the inner diameter of the mold must be substantially the same as the inner diameter of the small cylindrical opening formed in the elastic support 4).

If desired, the energy absorbing core 2 can be cast in situ within the cylindrical volume of the restraint 3. When using another manufacturing method for this device, molten core material is injected taking into account the thermal expansion of lead, and the core material contracts during the subsequent cooling, which causes the outer surface of the core material 2 and the inner surface of the restraining material 3 to It is necessary to avoid leaving too much space between them. For best results, the core 2 should be entirely confined on all sides, namely on the cylindrical side walls and on the top and bottom sides.

To work, this system is installed between the support of a structure, such as a bridge or building, and the foundation, such as a foundation pad. When a structure is subjected to vibrations induced by earthquakes, windstorms, etc., a shearing force sound is generated which is transmitted to the energy absorbing device, and the device receives this shearing force and causes distortion as shown in FIG. 3. As shown in the figure, the core material 2 deforms from its perfect circular cylindrical shape in response to the shearing force, and the restraining material 3 follows this movement. Since the restraint 3 has a rectangular cross-section, the adjacent wound layers will translate perpendicularly in the normal vertical alignment shown in FIG. Vertical support can be provided with a surrounding elastic layer 5 to prevent breakage or distortion of the material. Therefore, even if the core material 2 is tilted from vertical, it can maintain a substantially cylindrical shape. Furthermore, due to the flexibility of the wall surface formed by the inner surface of the individual wound layers of the restraining material 30 and the flexible arrangement of adjacent layers, [even if the core material 2 is sufficiently deformed and energy is dissipated, the integrity of the core material remains unchanged]. keep it. As mentioned above, most of the energy is generated and dissipated in the core 2, but the remaining energy is stored in the core 2 and the elastic support 4. This stored energy is used to return the heartwood material to its original mechanical condition. Additionally, some of the energy stored in the elastic support 4 is released, returning the core to its original geometry as shown in FIG.

Practical tests carried out on energy absorbing devices manufactured according to the present invention have shown that the service life of the improved energy absorbing device can be extended to 3 tons of restraining material constructed according to the prior art.
- It turns out that a similar device that does not have a similar length is also much longer.

In particular, the results of research carried out at the University of Auckland on knee sealants are described in the following publication: P. G. King, Mechanical Energy Dissipators for Earthquake-Resistant Structures, University of Auckland, Department of Civil Engineering Report 4228.
．． August 1980.

2, S., M., Bild ``Lead-Rubber Mechanical Energy Dissipators for Basic Insulation of Bridge Structures'' University of Auckland, Department of Civil Engineering Report 4289. August 1982.

To summarize the results, the thickness of 5 pieces is 1.273 (0,5
20 x 15 inch x 12 inch x 10.23 inch with inner layer
4 inch) lead-filled elastic supports were dynamically tested over a wide range of vertical loading and shear strain amplitudes.

Twenty-five combinations of vertical loading and shear strain were subjected to 5 cycles of displacement. The dissipated energy was measured from the characteristic yield strength, elastic and post-elastic stiffness as well as the area of load deflection hysteresis. The results of testing various unconfined lead shapes were compared with the results for the confined lead cylinder as described above. It was typically shown that the amount of water is twice as large when it is loaded.

In many applications, the frictional force between the lower surface of the top plate 7 and the abutting surface of the upper layer 5 and the frictional force between the upper surface of the bottom plate 8 and the abutting surface of the adjacent elastic layer 5 are as described above and in FIG. It is sufficient to partially demonstrate and perform nine new functions.

In some cases it may be desirable to provide an additional connection between the plate 7.8 and the inserted elastic support 4. This additional bonding involves gluing the plates 7, 8 to the end faces of the elastic support 4 by vulcanization, adhesive or the like. FIG. 4 shows another embodiment of the invention in which an active engagement force is applied between the plate 7.8 and the elastic support 4. FIG. As shown in this figure, the bottom surface of the top plate 7 is provided with a butt collar 111, which has the same geometry as the outer circumferential edge of the elastic support 4, as shown in a rectangular shape in FIG. The shape and dimensions of the collar 11 are such that when the plate 7 is pressed down into the resilient support 4, the uppermost part of the resilient support 4 enters the collar. The bottom plate 8 is provided with a similar abutting collar 12 on its upper surface, the collar 120 geometry and dimensions being substantially the same as the collar 11. During use, if there is a lateral displacement between the two plates 7, 8, this displacement is transmitted to the elastic support 4. This is actively transmitted not only by the frictional forces between the plates 7, 8 and the support 4, but also by mechanical forces between the collar 11.12 and the support 4. The collars 11, 12 are appropriately fixed to the plates 7, 8 by welding, brazing, gluing, etc.

FIG. 5.6 shows another embodiment of the invention, with active engagement between the plate 7.8 and the elastic support 40. FIG. As shown in the figure, the top plate 7 has a plurality of downwardly descending dowel pins 13 arranged in a predetermined I4 turn.In the figure, four pins 13i are arranged on the circumference at intervals of 900 degrees around the central axis of the core material 2.

A plurality of corresponding openings 14 are similarly provided in the uppermost layer of elastic material 5 and the uppermost layer of stiffener plate 6. The openings 14 can extend completely or partially through the top stiffener plate 6. The pins 13 and the openings 14 are arranged so that the pins 13 are pushed into the openings 14 when the top plate 7f is pushed into the elastic support 4 and lowered. Similarly, dowel pins 15 are arranged on the bottom plate 8, and corresponding openings are provided in the lowermost elastic member 5 and the lowermost stiffener plate 6. In a preferred embodiment, the top plate 7 and the bottom plate 8 are Although preferably integrated, it is possible in some cases for these plates to be integrated into a set of structural members or for the action of plates 7, 80 to be carried out by surfaces formed by a set of structural members. can.

For example, the bottom plate 8 may be the upper surface of the concrete support Arad of the power plant, and the C'%L top plate 7 may be the bottom of the reactor containment vessel of the power plant. While the above is a sufficient disclosure of the preferred embodiments of the present invention, other modifications may be made by those skilled in the art. without departing from its true spirit and scope. For example, although a particularly perfect circular cylindrical geometry has been described as a preferred embodiment, other geometries such as rectangular, trapezoidal, elliptical, etc. can be used. Furthermore, although the elastic support 4 is disclosed as having a rectangular geometry, it can be used with multiple parts including circular geometries. Furthermore, although the restraint has been described as a flat spirally wound cylinder, other shapes can be used depending on the geometry of the core 2. For example, when using a rectangular core, the restraint will have a similar rectangular geometry. Furthermore, if desired, the restraint material can be arranged in separate elements, such as flat circular rings, flat rectangular frames, etc., all vertically stacked one on top of the other.

The embodiment shown in Figures 1-6 has a restraint 3, hereafter referred to as a contacting helix. In this embodiment, each turn is in physical contact with the adjacent turn.The disadvantage of this configuration is that the bearing is vertically rigid and the attachment is formed by pressing in place, which can cause severe damage to the helix. It is about giving.

The other shapes shown in FIGS. 7 and 8 avoid these drawbacks. All of these structures have a confinement around the lead core 2 that is compressible to some extent in the vertical direction.

The fruit tII shown in FIG. 7! Helical coil 3 in A embodiment
is surrounded by an elastic body 17 such as urethane or silicone foam. In a preferred embodiment, such a construction is employed by hose manufacturers who use known techniques to manufacture water absorption hoses. By filling the spaces between the individual turns 30 of the helix with elastic material 17, an open helix structure is obtained which does not have the disadvantages of contact helices described above.

Another embodiment is shown in FIG. 8, in which the support l has a cylindrical lead core 2 and end plates 7, 8i. The lead core material 2 is wrapped with an elastic material 5 except for both ends. In this embodiment, a contact helix 3 wraps around the circumference of the lead core 2 together with a pawl or stiffener plate 6 . 50 layers of elastic material are spiral materials 3
The helix 3 is separated into individual windings in this embodiment in layers between the windings and the individual stiffener plates 60. In FIGS. 7 and 8, the continuous helix 3 or the separation Instead of the spiral portion 3, rings separated by an elastic material may be stacked and used.

In all embodiments, when the flexible column walls have some elasticity in the vertical direction, the helices 3 may be separated so that they do not touch each other.

The presence of elastic material between the layers of helical material or the layers of ring material does not affect the ability of the restraining means to confine the lead core material 2, providing the benefits described above with reference to FIGS. 1-6.

The embodiment shown in FIG. 9 includes a top plate 7, a bottom plate 8 and an elastic material 5.
and stiffeners 6, with openings 9 passing through the top plate 7 and the bottom plate 8, allowing these plates to be fixed to a structure or foundation.

A hole corresponding to the cross section of the core material 2 is formed in the top plate 7'f.

This hole is threaded on the inside surface. # Yazzo 19 has appropriate diameter and is threaded on the outside surface.

Screw the middle plate 7'19 through the top plate 7 and insert the core material 2? I
Helps in confinement in the i-direction. When pushing the cap 19i downward, care must be taken to prevent the top plate 7 from coming off the elastic layer 5. When this device is placed under a building, it will not come off due to the weight of the structure applied to the top plate 7.

Other geometries and arrangements discussed with respect to the embodiments of FIGS. 1-6 may similarly apply with respect to FIGS. 7-9; therefore, the scope of the invention is limited by the above description and illustrations. shall not be construed as such, but shall be defined by the scope of the claims.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a preferred embodiment of the present invention, FIG. 1 M2 is a sectional view taken along line 2-2 in FIG. 1, and FIG. 4 is a sectional view similar to FIG. 2 showing another embodiment of the present invention, and FIG. 5 is a sectional view similar to FIG. 4 showing another embodiment of the present invention. Figure 6 is a plan view taken along line 6--6 of Figure 5; Figures 7.8 and 9 relate to two preferred embodiments of the invention;
The figure is a sectional view similar to FIG. 2 showing another embodiment of the present invention, and FIG. 8 is a sectional view similar to FIG. 7 showing a roughly other embodiment of the invention. FIG. 9 is a sectional view similar to FIG. 8 showing another embodiment of the present invention. The embodiments of FIGS. 1 to 6 are variations that embody the features of the present invention by inserting an elastic material between at least some adjacent layers of the restraining material. 1. Energy absorbing device; 2. Energy absorbing means, 3... Restraining means, 4... Elastic support (pad), 5... Elastic material, 6... Stiffener material, 7, 8...
・Connecting plate means, 11.12...butting means, 13,1
5... Dowel means, 14.16... Opening, 17...
Elastic body, 19...Medium yag・

Claims (1)

[Claims] 1. Suitable to be interposed between two members in order to absorb energy due to motion induced between the two members, and capable of being engaged with one of the two members. a first end that is engageable with the other one of said two members; and a plastically periodic end that extends between said first and second ends. a deformable energy absorbing means, the energy absorbing means being arranged around the energy absorbing means in a region between the first and second ends, while motion is induced between the two members; restraining means having a flexible wall that confines and deforms the energy absorbing means, wherein the restraining means deforms at least some of the flexible wall. A periodic shear energy absorbing device characterized in that it has an elastic layer between adjacent layers. 2. The apparatus of claim 1, wherein said restraining means comprises a flat member wound generally helically around the outer surface of said energy absorbing means. 3. The device of claim 1 further comprising a resilient support disposed around the restraining means between the first and second ends. 4. The device of claim 3, wherein the elastic support has alternating layers of elastic material and stiffening material layers. 5. The device according to claim 4, wherein the restraining means has the elastic material layer, the spirally wound plate member layer, and the stiffener material layer stacked alternately. 6. said restraint means comprising a stack of flat members surrounding the outer surface of said energy absorbing means, said flexible wall surface being formed by flat members, at least some of which are separated by said elastic layer; 2. The device of claim 1, wherein: 7. The apparatus of claim 1, wherein said energy absorbing means comprises a lead core material. 8. further comprising a top plate member connected to the first end and a bottom plate member connected to the second end;
An apparatus according to claim 1. 9. At least one of the top and bottom plate members further comprises abutment means for transmitting force between the plate member and the cooperating end.
Apparatus described in section. 10. The apparatus of claim 9, wherein each said end has a rectangular perimeter and said abutment means has a rectangular perimeter surrounding said perimeter. 11. It has a top plate member connected to the first end and a bottom plate member connected to the second end, and at least one of the top and bottom plate members is connected to the plate member. an abutting means for transmitting force to and from the energy absorbing means; and an elastic support formed with a plurality of openings extending longitudinally from an end adjacent to at least one plate member, the abutting means 6. The apparatus of claim 5, wherein said dowel member has a corresponding plurality of dowel members each cooperatively received in said plurality of apertures. 12. A cap as claimed in claim 1, having a threaded aperture drilled through the top plate in alignment with the energy absorbing means and a cap capable of being screwed into the aperture to axially confine the energy absorbing means. The device according to scope item 11. 13. A periodic shear energy absorbing device for absorbing energy induced between two members, comprising: a first connecting means to be connected to a first of said two members; a second connecting means to be connected to a second of the two members; a plastically cyclically deformable energy absorbing means connected between said first and second connecting means; restraining means arranged around the energy absorbing means in the region between the first and second connecting means, the restraining means being arranged such that movement is induced between the first and second connecting means. a flexible wall that confines and deforms the energy absorbing means during the period of time, the flexible wall having an elastic layer between adjacent layers of the flexible wall. Shear energy absorption device. 14, said restraint means comprising a flat member wound generally helically around the outer surface of said energy absorbing means, said flexible wall surface being formed by discrete layers of wrapping material, at least some of said layers; 14. The device of claim 13, wherein the elastic layer is separated from adjacent layers by the elastic layer. 15. said restraint means comprising a stack of flat members surrounding the outer surface of said energy absorbing means, said flexible wall surface being formed from flat members, at least some of said members being separated by said elastic layer; 14. The device according to claim 13, wherein: 16. The apparatus of claim 14, wherein said flat member is made of spring steel. 17. The apparatus of claim 14, wherein said flat member is made of aluminum. 18. The apparatus of claim 13 further comprising a resilient support disposed between said first and second connecting means and surrounding said resilient means. 19. The apparatus of claim 18, wherein each of said first and second coupling means includes abutment means for transmitting force to said resilient support. 20. The apparatus of claim 19, wherein said abutting means has a shoulder in contact with the outer periphery of said elastic support. 21. The apparatus of claim 18, wherein the elastic support comprises alternating layers of elastic and stiffening materials. 22. The apparatus of claim 18, wherein said restraining means comprises alternating layers of said elastic material, spirally wound flat members, and said stiffening material. 23. The apparatus of claim 18, wherein said restraining means comprises alternating layers of said resilient material, stacked flat members, and said stiffening material. 24. The resilient support has a first plurality of openings extending from the top surface of the support down into the top layer of stiffening material and a second plurality of openings extending from the bottom surface of the support into the top layer of stiffening material. extending up into the bottom layer and said abutment means having first and second dowel means, each first dowel means being received in a corresponding one of said plurality of openings; Extending downwardly from said first connecting means and extending upwardly from said second connecting means such that each second dowel means is received in a corresponding one of said plurality of openings. range 2nd
The device according to item 2. 25. The device of claim 10, wherein said energy absorbing means comprises a lead core material.