JP2001342749A - Vibration control member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration control member with high stiffness and strength with respect to a main frame, capable of bringing about vibration reduction effect. SOLUTION: The vibration control member is composed of a visco-elastic damper 2 and a friction damper 3, which are assembled in series. The friction damper 3 is formed by pressing a friction sliding member 32 and a pressure contact member 33 through the medium of a friction material 31 by a cramping means 4. An upper limit to the deformation of the damper 2 is set in such a manner as to become the ratio between the sliding load of the friction damper 3 and the stiffness of the damper 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping member for attenuating vibration of a building structure due to an earthquake or wind, and more particularly to a vibration damping member combining a viscoelastic damper and a friction damper. .

[0002]

2. Description of the Related Art Generally, a method of installing a damper device in a building frame has been frequently used as a method of reducing vibration of a steel building structure due to an earthquake or a strong wind. Conventionally, this type of vibration damper includes (a) a viscoelastic damper and (b) a friction damper.

[0003] By the way, (a) effectively exerts a vibration damping effect on vibrations from a relatively small amplitude range such as a wind vibration and a small / medium-scale earthquake to a large earthquake. However, since the history shape expands similarly to the vibration, the force acting on the damper during a large earthquake tends to be excessive,
This has the disadvantage that the main structural member is damaged. On the other hand, (b) does not absorb energy in the elastic range below the sliding load, and thus has no damping effect on small and medium-sized earthquakes. There is also a problem that residual deformation and stress occur after disturbance input. Thus, (a) and (b)
Each has advantages and disadvantages.

Therefore, as a technique for overcoming the disadvantages (a) and (b), for example, Japanese Patent Application Laid-Open No. 9-26880
Japanese Unexamined Patent Application Publication No. 2 (vibration damper) and Japanese Patent No. 2987331 (brace structure using a viscoelastic damper) are known.

In Japanese Patent Application Laid-Open No. Hei 9-268802, a first damper made of a viscoelastic / viscous damper and a second damper made of a steel damper or a friction damper are provided between two relatively displaceable members of a building. A vibration damper connected in series is attached (Prior Art 1).

[0006] The brace described in Japanese Patent No. 2987331 is constructed by connecting a viscoelastic damper and a friction joint (hereinafter, referred to as a friction damper) by a connection plate in which a bracket is sandwiched by bolts. Technology 2).

[0007]

According to the prior art 1 or 2 described above, when an excessive load is applied, the damping function of the viscoelastic damper is maintained by the friction damping force, so that a wider range of vibration can be obtained. It has been proposed to obtain a damping effect in the area.

However, in the above prior art 1, since the specific structure of the damper device is not described, there are many unclear points in practical vibration damping effect, device cost, durability, reliability, and the like.

Further, the prior art 2 has the following problem. <A> In a friction damper, since a normal structural member is used as a friction material, the frictional force and restoring force characteristics are often unstable. This is because, in the case of ordinary structural members, meshing between materials, slippage and the like occur irregularly. Also, temperature, humidity,
It tends to fluctuate due to frictional wear caused by repeated loads due to small and medium earthquakes and strong winds. <B> In the case of long-term service to structures,
Adhesion between irons also becomes a problem. <C> As a structural member, the bolt has a high rigidity, so that a decrease in plate thickness due to wear on the friction surface sensitively affects the bolt axial force and induces a significant decrease in the bolt axial force. For this reason, it is extremely difficult to secure the required frictional force. <D> Since the frictional force is directly applied to the load of the viscoelastic damper, the behavior of the viscoelastic damper becomes irregular due to the instability.

On the other hand, according to recent studies by the inventors, when a vibration damping member is incorporated into a main frame, in order to produce an optimum vibration damping effect on the rigidity and proof strength of the main frame, the rigidity of the vibration damping member is reduced. It is necessary to adjust the yield force and energy absorption,
The degree of freedom of adjustment of the vibration damping member proposed here is remarkably increased as compared with the case of using a single device or a single device. Therefore, it is possible to more efficiently reduce the response displacement and the response acceleration of the structure caused by a disturbance such as an earthquake.

In a vibration damping member combining a friction damper and a viscoelastic damper, it has been confirmed by experiments and analysis using various earthquake inputs that the former slip can suppress the deformation of the latter to a certain value or less. Was done. It was also found that this deformation upper limit was a value obtained by dividing the former sliding load by the latter rigidity when sliding did not occur. Thus, regardless of the magnitude of the earthquake or wind, deformation of the viscoelastic damper can be suppressed and destruction can be prevented. Further, the required operating range of the friction damper is also obtained as a value obtained by subtracting the upper limit value from the request for deformation of the whole damping member.

Further, at present, the rigidity and energy absorbing ability of the viscoelastic material in the viscoelastic damper depend on the temperature. At low temperatures the viscoelastic material is hard, which increases the restoring force when used alone and vice versa at high temperatures. An increase in the restoring force leads to an increase in energy absorption, but leads to an increase in the stress of the mounting portion, structural members such as beams and columns, and the foundation, and causes damage to these portions. Here, by combining the friction damper, the restoring force can be suppressed to a certain level as a whole device,
The above structural members and foundations are protected, and the design is facilitated.

[0013]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object of the present invention is to provide a vibration damping member which can satisfy the following items at the same time and is excellent in economy. . <a> Stable friction force and restoring force characteristics can be obtained. <B> The degree of freedom in selecting the friction coefficient and friction damping force is high. <C> The rigidity, proof strength, and dimensions required for the entire vibration damping member are not likely to be restricted. <D> To prevent the viscoelastic material from breaking by controlling the deformation of the viscoelastic damper against various earthquakes and wind loads. <E> Efficiently design each damper by evaluating the deformation requirements of the friction damper and viscoelastic damper.

[0014]

In order to achieve the above object, a vibration damping member according to a first aspect of the present invention includes a viscoelastic damper that generates a damping force by deformation of a viscoelastic body;
A damping member in which a friction damper that generates a friction damping force by friction sliding is connected in series, and the friction damper is formed by pressing a friction sliding member and a pressure contact member with a fastening means via a friction material. The upper limit of the deformation of the viscoelastic damper is set so as to be the ratio between the sliding load of the friction damper and the rigidity of the viscoelastic damper.

The invention according to claim 2 is characterized in that the minimum thickness of the viscoelastic body is obtained by dividing the upper limit of deformation of the viscoelastic damper by the limit shear strain value of the viscoelastic body. A vibration damping member according to claim 1.

The invention according to claim 3 is the vibration damping member according to claim 1 or 2, wherein the friction sliding member has a cross-shaped cross section.

The invention according to claim 4 is the vibration damping member according to claim 1 or 2, wherein the friction sliding member has an H-shaped cross section.

According to a fifth aspect of the present invention, in the vibration damping member according to the first or second aspect, the friction sliding member is configured to have a square-shaped cross section.

Further, the invention according to claim 6 is characterized in that the fastening means is constituted by fastening the friction sliding member and the pressure contact member with a bolt and a nut via a friction material. Item 6. The vibration damping member according to any one of items 5.

[0020]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

<A> Basic Structure of Damping Member FIG. 1 shows an embodiment of a damping member 1 according to the present invention, wherein the damping member 1 is composed of a main frame composed of columns a and beams b. It is a conceptual diagram which illustrates the case where it is incorporated in A and used as a brace material. FIG. 2 is an enlarged view of a part of the vibration damping member 1. First, the vibration damping member 1 of the present invention
Basically, it includes a viscoelastic damper 2 that generates a damping force by shear deformation of the viscoelastic body, and a friction damper 3 that generates a friction damping force by friction sliding. The viscoelastic damper 2 is not particularly limited in the present invention. For example, a known viscoelastic damper is used in which a viscoelastic body is sandwiched between several metal plates and vibration energy is attenuated by shear deformation of the viscoelastic body generated between the metal plates. May be used. On the other hand, the friction damper 3 is formed by pressing the friction sliding member 32 and the pressure contact member 33 with the fastening means 4 via the friction material 31. And
The viscoelastic damper 2 and the friction damper 3 are connected in series along the axial direction of the member. At this time, the viscoelastic damper 2
As the deformation upper limit value, the sliding load of the friction damper 3 and
It is preferable to set the ratio of the (equivalent) rigidity of the viscoelastic damper 2. This makes it possible to suppress deformation of the viscoelastic damper and prevent destruction, regardless of the magnitude of disturbance such as an earthquake or wind. The advantages of both can be utilized, and the damping effect can be maximized. Further, the required operating range of the friction damper can be easily obtained by subtracting the upper limit from the required overall deformation.

Further, the minimum thickness of the viscoelastic body is obtained by dividing the upper limit of deformation of the viscoelastic damper 2 by the critical shear strain value of the viscoelastic body. It can be minimized. Thus, by combining with the friction damper 3, the viscoelastic damper 2 can be minimized and the reliability can be improved. Also,
The restoring force of the vibration damping member or the whole device can be suppressed to a certain level, and the design thereof becomes easy. Further, the dependence of the rigidity and the energy absorption capacity of the apparatus as a whole on the temperature can be remarkably reduced, so that the responses of the main frame and the entire structure can be prevented from being sensitive to temperature changes.

Hereinafter, embodiments of the friction damper according to the present invention will be described more specifically with reference to the drawings.

<A> First Embodiment As shown in FIGS. 2 (a) and 2 (b), a friction damper 3 according to the present invention comprises a friction member 31 formed by pressing a friction member 31 having a U-shape in a sliding direction. , The upper and lower protruding edge portions 3 of the member 33
3a, 33b and the friction sliding member 32,
The protruding edge portions 33a and 33b and the friction sliding member 32 are formed by being pressed by the tightening means 4. In the example shown in the figure, the fastening means 4 includes the protruding edges 33a, 33b and the frictional sliding member 32.
And a high-strength bolt 41 penetrating the friction material 31 at the same time, and a nut 42 screwed to the bolt 41. The pressing member 33 has a hole 33 for sliding.
The contact member 33 and the friction sliding member 32 are relatively slidable along the direction of the hole.

As the friction material 31, a material having a required friction coefficient and excellent in durability and reliability can be selected and used. As such a material, for example, a brake pad is preferable. Further, the friction sliding member 3
2, both surfaces thereof are brought into contact with the opposing surfaces of the friction materials 31, 31, for example, carbon steel for general structure (SS400,
SM490), and if necessary, a steel material such as one subjected to hard chrome plating or stainless steel (SUS430) is used. On the other hand, the pressing member 33 and the friction sliding member 32
A gap is provided between the first and second ends to allow relative movement between the two. If necessary, a slit may be provided in the web portion 33d of the press-contact member 33 so as to be relatively movable. Thus, by combining the friction coefficient of the friction material 31 and the tightening means 4 (the pressing force and the magnitude of the surface pressure), the friction force can be easily set to an arbitrary value.

With the above structure, when the tension / compression force acts on the friction damper 3, the friction sliding member 32 and the friction material 3
In addition to absorbing the energy by the frictional force due to the relative sliding of No. 1 and using a high-strength bolt incorporating a disc spring (not shown), the pressing force (surface force) is kept constant, and It is possible to obtain stable friction and restoring force characteristics.

<B> Second Embodiment FIG. 3 shows a second embodiment of the friction damper 5 according to the present invention. In this case, even when the friction coefficient of the friction material 31 in the first embodiment is constant, a larger frictional force or yield load is obtained, and the rigidity of the vibration damping member 1 is increased. It employs a cross-shaped member. In the example shown in the figure, the cross-section steel 51
Use The cruciform steel member 51 includes four steel plates (wings) 51a, 51b, 51c, and 51d having required dimensions, which are vertically crossed and welded to each other.
The attachment portion (not shown) and the viscoelastic damper 2 are connected. A frictional force forming portion F is provided on the wing portion.

The above-described frictional force forming portion F will be described in detail. Each of the steel plates 51a, 51b, 51c, 51d is formed by a pair of pressure contact plates 6, 6, respectively.
1 and 31 and a high-strength bolt 4
1. Fastened by nut 42. High strength bolt 41
Uses high-tensile steel, and penetrates through the press contact plates 6, 6, the friction members 31, 31, and the steel plates 51a, 51b, 51c, 51d at the same time. Further, the steel plates 51a, 51b, 51
The sliding holes 5a are formed in c and 51d in the axial direction of the cruciform steel member 51, and the press contact plates 6, 6 and the cruciform steel member 51
It is relatively slidable in the direction of the hole 5a.

The four steel plates 51a, 51b, 51c,
51d is basically made of the same material and has the same thickness, and both surfaces contacting the friction members 31, 31 may be subjected to the surface treatment described above in the first embodiment, if necessary. . The friction materials 31, 31 are made of the same material but have a shorter length than the friction material 31 in the first embodiment described above. In addition, a steel plate having a length dimension larger than the friction members 31, 31 is used for the press contact plates 6, 6.

In the second embodiment, similarly to the first embodiment, when the friction damper 5 is pulled or compressed by a vibration of the structure due to an earthquake or a strong wind, the friction materials 31, 31 are applied to the friction materials 31, 31. On the other hand, four steel plates 51
a, 51b, 51c, and 51d slide together, and as a result, an energy absorbing action is performed by the frictional force.

Even if a large compressive force acts on the cross-section steel material 51, buckling hardly occurs due to the buckling restraining effect due to its cross-sectional characteristics. In the present embodiment, the friction material 31,
31 are provided more than in the first embodiment,
As a result, the frictional force or the damping force is increased as compared with the first embodiment, and the vibration damping effect can be more effectively exerted even for a larger earthquake. Furthermore, due to an increase in the frictional force (sliding load), the deformation upper limit value of the viscoelastic damper 2 having the same rigidity becomes larger than that of the first embodiment, and as a result, the damping performance of the viscoelastic damper 2 is also improved. become.

<C> Other Embodiments FIG. 4 shows a third embodiment of the friction damper according to the present invention, and FIG. 5 shows a fourth embodiment. In the third embodiment, the friction sliding member employs a shape member having an H-shaped cross section. In the example shown in the figure, the section is made of an H-shaped steel member 7a. The upper and lower flanges 7b and 7c of the H-shaped steel member 7a are provided with the same friction force forming portions F as in the second embodiment, as shown in FIG. Here, the description thereof is omitted. Also,
If necessary, a frictional force forming portion F may be provided on the web 7d. In addition, outside the upper and lower flanges 7b and 7c,
One press contact plate having a larger size than the press contact plate 6 as shown may be provided (see FIG. 5). Correspondingly,
One piece of friction material may be used.

In the fourth embodiment, the friction sliding member employs a hollow member 8a having a square cross section. As shown, the hollow mold member 8a includes an upper mold member 8b having a downward groove and a lower mold member 8c having an upward groove.
And are connected via two intermediate members 9. As in the second embodiment, in order to generate a frictional force, the upper profile 8b and the lower profile 8c are each provided with the above-described frictional force forming portion F as shown in FIG. Here, the description is also omitted. Further, if necessary, the intermediate member 9 may be provided with a frictional force forming portion F.

[0034]

As described above, the vibration damping member according to the present invention has the following effects. <B> Stable friction force and restoring force characteristics can be obtained. <B> The degree of freedom in selecting the friction coefficient and the friction damping force can be increased. <C> The degree of freedom in designing rigidity, proof stress and dimensions required for the entire vibration damping member can be increased. <D> By controlling the deformation of the viscoelastic damper against various earthquakes and wind loads, it is possible to prevent the viscoelastic material from being broken. <E> By evaluating the deformation requirements of the friction damper and the viscoelastic damper, the design of each damper can be performed efficiently. According to <f>, <a> to <f>, it is possible to provide a vibration damping member having high rigidity and high proof stress and improving the damping performance. <G> Since the dependence of the rigidity and energy absorption capacity of the entire vibration damping member on temperature can be remarkably reduced, it is possible to prevent the response of the entire structure from becoming sensitive to temperature changes.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing an example of use of a vibration damping member according to the present invention.

FIG. 2A is a cross-sectional view of the first embodiment of the friction damper according to the present invention. FIG. 2B is an enlarged perspective view of a part of FIG.

3A is a cross-sectional view of a friction damper according to a second embodiment of the present invention, and FIG. 3B is an enlarged perspective view of a part of FIG.

FIG. 4 (a) is a transverse sectional view of a third embodiment of a friction damper according to the present invention, and FIG. 4 (b) is an enlarged perspective view of a part of FIG. 4 (a).

5A is a cross-sectional view of a friction damper according to a fourth embodiment of the present invention, and FIG. 5B is an enlarged perspective view of a part of FIG. 5A.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vibration suppression member 2 Viscoelastic damper 3, 5, 7, 8 Friction damper 31 Friction material 32 Friction sliding member 33 Pressure contact member 33a Upper protruding edge 33b Lower protruding edge 33c Sliding hole 33d Web 4 Tightening means 41 Bolt 42 Nut 51 Cross-shaped friction sliding member 5a, 7e, 8d Sliding hole 6 Pressure contact plate F Friction force forming part

Claims (6)

[Claims] 1. A vibration damping member comprising a viscoelastic damper that generates a damping force by shear deformation of a viscoelastic body and a friction damper that generates a friction damping force by frictional sliding in series, wherein the friction damper is , Formed by pressing the friction sliding member and the pressure contact member with the fastening means via the friction material, and setting the upper limit of deformation of the viscoelastic damper to be the ratio of the sliding load of the friction damper to the rigidity of the viscoelastic damper. A vibration damping member, characterized in that: 2. The vibration damper according to claim 1, wherein a minimum thickness of the viscoelastic body is obtained by dividing an upper limit of deformation of the viscoelastic damper by a limit shear strain value of the viscoelastic body. Element. 3. The vibration damping member according to claim 1, wherein the friction sliding member has a cross-shaped cross section. 4. The vibration damping member according to claim 1, wherein the friction sliding member has an H-shaped cross section. 5. The vibration damping member according to claim 1, wherein the friction sliding member has a square cross section. 6. The tightening means according to claim 1, wherein the frictional sliding member and the pressing member are fastened with a bolt and a nut via a friction material. A vibration damping member according to any one of the preceding claims.