The Aseismic Analysis Of Shearing Building By Variable Damper

The damping is an important parameter in seismic design of buildings and it represents the energy dissipation of the structure in the earthquake. It’s beneficial if the damping of the structure raise up. Research shows that in the last decades, damping properties of the structures are variable during vibration and the damping ratio will increase with the deformation. So, taking damping of the structure in design principle as a fixed constant is unreasonable. How to endow the damping ratio of the building an appropriate value has become an urgent problem.At present, domestic and foreign scholars have studied on this issue and proposed expressions about variable damping ratio. However, some of them were proposed for structural members, some were proposed for the entire building, none of them is proposed to describe the damping of the building when the building occur plastic deformation.Aiming at the above problems, the main works of this paper are as follows:(1)The change rule of damping properties and the relationship between deformation and damping ratio of buildings in structural vibrations are analyzed. Analysis found that the damping ratio become larger as the increase of structural deformation(2)This paper proposes a new expression about damping ratio and the deformation of shear frame structure.(3)Finally, the elastic and elastic-plastic time-history analysis is carried out for a three-story structure in twelve cases. For a three-story structure in12cases with time-history method. Time history response curves under different working conditions are given. By comparing with other expressions that’s confirmed the damping model purposed by the paper is up to the change rule of damping properties of the buildings. It’s simple and easy to calculate for shear frame structures.