Study On Seismic Behavior Of Ring Composite Viscoelastic Damping Bearing

In this article,a new type of annular composite viscoelastic damping support is designed for the large horizontal long-span displacement space structures in the earthquake or wind vibration and make experimental and finite element analysis on it,and finally,the restoring force model is proposed according to the analysis results.The annular composite viscoelastic damping support is compose of lead core,low yield steel and rubber energy dissipation component,which can meet the designing idea of “close contact,common force”.The damping support can not only be used in the large-span space structure shock absorption,but also in the mechanical equipment,which has a broad application prospect.According to the structural characteristics of the annular composite viscoelastic damping bearing are designed with the number of lead cores as variable and tested in a low cycle.The conclusion:(1)The vertical deformation is less than 10% of the rubber layer total thickness when the vertical loading force of the annular composite viscoelastic bearing reaches 200kN;(2)With the increase of loading amplitude,the hysteresis curve formed by the experiment is basically full,but the formed hysteresis loop can basically envelop the hysteresis loop which formed by the the loading amplitude of previous stage,indicates that the annular composite viscoelastic damping support has good energy dissipation performance;(3)Increasing the number of lead cores plays a positive role on improving the energy dissipation performance of annular composite viscoelastic damping supports and improves annular composite visicoelasticity effectively;(4)On the premise of excluding the unfavorable factors such as the original defect of the test piece,the measurement data error,and the accumulation of test damage,it is considered that the effect of the loading frequency on the energy dissipation performance of the ring-shaped composite viscoelastic damping bearing is negligible.On the basis of theoretical and experimental research,through establishing finite element analysis model,with a low yield steel plate and rubber plate thickness ratio,the layer number ratio and lead core arrangement as variable to design 15 groups of annular composite viscoelastic bearing specimens.From the hysteresis curve,the equivalent damping ratio and energy consumption coefficient,we can get the following conclusions:(1)As the total thickness ratio of low yield steel plate and rubber increase,the presentation of equivalent damping ratio and the energy dissipation coefficient increases then decreases,suggested thickness ratio between 0.45 ~ 0.90 is advisable;(2)With the premise that the thickness ratio of composite viscoelastomer unchanged,it is recommended that the ratio oflow yield steel plate and rubber layers should not be less than 3:4;(3)With the premise that the annular composite viscoelastic damping support has the same lead core yield shear force,it is recommended that the center angle of lead core inside the annular composite viscoelastic damping support should be between 60° and 90°.