JPH07207985A - Damping device of building by means of eccentric brace damper - Google Patents

Abstract

PURPOSE:To damp a building simply and accurately by installing both and lower arm parts and an eccentric brace, being composed of a central deforming part being connected replaceably with steel material of very low yielding point, in a skeleton consisting of a column and a beam. CONSTITUTION:An eccentric brace 3 is installed in space between both column- beam joined parts at both ends of a diagonal of a skeleton consisting of a column 1 and a beam 2. In this case, the eccentric brace 3 is composed of an upper arm part 3a and a lower arm part 3b joining to the column-beam joined part and a central deforming part 3c lying between both these upper and lower arm parts 3a and 3b. In this connection, the whole or a part of this central deforming part 3c is made up of very low yielding point steel. With this constitution, at the time of earthquake or the like, bending moment in the central part of the eccentric brace 3 is maximized and thereby the central deforming part 3c is bent and deformed. Further if this deformation reaches to a plastic deformation, such a function as absorbing vibro-energy is mainfested as hysteretic absorptive energy, and thus a vibration is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is particularly applicable to steel structures and other R structures.
The present invention relates to a vibration control device for a building using an eccentric brace damper applied to C, SRC and mixed structures.

[0002]

2. Description of the Related Art Conventionally, as a vibration control structure used for a frame structure, as shown in FIG. 4, a brace C is attached to a structure surrounded by a column a and a beam b, and the brace C is provided between the upper part and the upper beam of the brace. There is a structure in which a vibration damping panel d is attached. When interlayer deformation occurs in this frame, the damping panel receives shearing force and the brace also receives axial force. At this time, the vibration damping panel undergoes shear deformation and absorbs the vibration energy of the building as its hysteresis absorption energy to reduce the vibration of the building. The braces are slightly deformed by the axial force that enters the braces.

[0003]

In the conventional vibration damping structure, even if the brace is deformed, the vibration damping effect is obtained mainly by the deformation of the vibration damping panel. The amount of shearable deformation of the damping panel is limited by the shape and size of the panel. In a building with high floor height, when damping is performed by combining the damping panel and damping brace described above, the layer deformation may increase and exceed the usage limit of the damping panel, and the structure becomes complicated. To do.

The present invention has been proposed in view of the problems of the above-mentioned prior art, and its object is to suppress the vibration of a building with a relatively simple structure and to obtain a reliable vibration control effect. The point is to provide a device.

[0005]

In order to achieve the above-mentioned object, a vibration damping device for a building using an eccentric brace damper according to the present invention has an eccentric brace arranged in a frame composed of columns and beams. The eccentric brace is composed of upper and lower arm portions and a central deformable portion interposed between the both arm portions, and the tip end portions of the both arm portions are connected to the pillar and the beam, and one of the central deformable portions is formed. Part or all is made of steel having a lower yield point than general steel.

According to a second aspect of the present invention, the centrally deformed portion of the eccentric brace can be replaced.

[0007]

Since the present invention is constructed as described above,
When a frame composed of columns and beams undergoes interlayer deformation due to an earthquake or wind, the entire eccentric brace receives an axial force in the direction of expansion or contraction. At this time, the moment of the central portion becomes maximum, and bending deformation occurs.

However, since a part or all of the centrally deformed portion interposed between the upper and lower arm portions of the eccentric brace is made of a steel material having a lower yield point than general steel materials,
When a plastic deformation is caused by applying a slight force to the eccentric brace and the building vibrates due to an earthquake or the like, the vibration energy is absorbed as hysteresis absorption energy even when the deformation is small, and the vibration is reduced.

[0009]

The present invention will be described below with reference to the illustrated embodiments. An eccentric brace 3 made of H-shaped steel is arranged between two column-beam joints located at both ends of a diagonal line of a frame composed of a column 1 and a beam 2. The eccentric brace 3 has an upper arm portion 3a and a lower arm portion 3b whose front ends are joined to a beam-column joint portion, and upper and lower arm portions 3a and 3b.
It is composed of a steel plate having a yield point lower than that of general steel, for example, a central deformed portion 3c made of an extremely low yield point steel, in which flange portions are joined together by a joining plate 4 and bolts 5.

All or part of the central deformed portion 3c is made of ultra low yield point steel. Since the illustrated embodiment is configured as described above, at the time of an earthquake or the like, the central portion of the eccentric brace 3 has the maximum bending moment, and the central deformed portion 3c made of ultra-low yield point steel is easily formed. When bending deformation occurs and this deformation leads to plastic deformation, a function of absorbing vibration energy as hysteretic absorption energy is developed, and vibration is reduced.

The central deformed portion 3c of the eccentric brace 3 is repeatedly plastically deformed, and residual deformation occurs. However, since the central deformed portion 3c is bolted to the upper and lower arm portions 3a and 3b, conversion is possible. . FIG. 3 shows another embodiment of the present invention, in which the eccentric brace 3 is doubly attached. In the figure, the same parts as those in the above embodiment are designated by the same reference numerals.

[0012]

As described above, the vibration damping device for a building according to the present invention has the eccentric brace arranged in the frame composed of the column and the beam, and the brace is arranged in the upper and lower arm portions and the central deformed portion. By constructing part or all of the central deformation part of steel material having a lower yield point than general steel materials, the central deformation part of the eccentric brace causes plastic deformation with a small force, so the building will be damaged by the earthquake. When vibrating, the vibration energy is absorbed as hysteresis absorption energy even from a small deformation, and the vibration of the building is reduced.

By adjusting the length, cross section, shape and eccentricity of the centrally deformed portion, it is easy to set the yield displacement of the brace and the maximum deformation amount, and it is possible to follow a large deformation.
Moreover, the structure becomes simple. According to the second aspect of the invention, since the centrally deformed portion of the eccentric brace is configured to be replaceable, the centrally deformed portion repeatedly undergoes plastic deformation and when residual replacement occurs, it is easy to replace it. It can be replaced as needed, for example, after a large earthquake, it may be replaced as needed.

[Brief description of drawings]

FIG. 1 is an elevational view showing an embodiment of a building vibration damping device using an eccentric brace damper according to the present invention.

FIG. 2 is an explanatory diagram showing a deformed state of the vibration damping device.

FIG. 3 is an elevational view showing another embodiment of the present invention.

FIG. 4 is an elevational view showing a conventional vibration damping device.

[Explanation of symbols]

 1 pillar 2 beam 3 eccentric brace 3a upper arm part 3b lower arm part 3c central deformation part 4 joining plate 5 bolt

Claims (2)

[Claims] 1. An eccentric brace is provided in a frame composed of columns and beams, and the eccentric brace is composed of upper and lower arm portions and a central deformable portion interposed between the both arm portions. The eccentric brace damper is characterized in that the tip ends of the both arm portions are connected to the pillars and beams, and part or all of the central deformation portion is made of a steel material having a lower yield point than general steel materials. Vibration control device for buildings. 2. The vibration control device for a building with an eccentric brace damper according to claim 1, wherein the centrally deformed portion of the eccentric brace is replaceable.