Research On Seismic Performance Of Cam Response Amplification Device Of Viscous Damper And Shear-type Isolated Structure

Seismic isolation technology can effectively reduce the damage caused by earthquakes to buildings,and has been widely used in practical engineering.However,due to the extremely uncertainty of the ground motion,there is strong probability that the isolated building will experience extremely rare earthquake and near-fault ground motions in their design reference period,resulting in excessive horizontal displacement of the seismic isolation layer.The displacement response of the isolation layer largely restricts the overall performance and safety of the isolation system,and the displacement of the isolation layer must be limited if necessary.At present,most layer stoppers use the various types of passive dampers to serve as,but there are many deficiencies,such as the travel is restricted,large damping force,and high manufacturing cost.Inspired by the response amplification mechanism,this article has independently developed a new type of Cam Response Amplification Displacement Restrictor Device of Viscous Damper(CRAD-VD),which has displacement,velocity and force amplification,and the additional viscous damper is not related to the displacement of the isolation layer.In this paper,through theoretical derivation,experimental research and numerical analysis methods,the CRAD-VD mechanical model,the amplification response,the economy,and the seismic performance of the isolation limit results were systematically studied.The main research work and achievements are as follows:1、Derivation of calculation formula for CRAD-VD: This paper summarized the research status of isolation-limiting devices and response amplification mechanisms at home and abroad,and introduced the idea and working mechanism of the viscous damper cam-type response amplifier(CRAD-VD).According to the characteristics of CRAD-VD’s design structure and motion transformation,CRAD-VD’s restoring force model formula,hysteresis curve and magnification expression are deduced in detail.2、CRAD-VD experimental study: Based on CRAD-VD design concept and test loading equipment conditions,a CRAD-VD test device was designed and manufactured and pseudo-static load test was conducted,meanwhile,the feasibility and reliability of the device operation were tested.Through the tests,the hysteresis curves of CRAD-VD and additional viscous dampers under different loading conditions were obtained.Using CRAD-VD theory to restore the force model formula,using MATLAB to simulate the test process,the CRAD-VD hysteresis curves obtained from real and simulated experiments were compared,and the accuracy of CRAD-VD theoretical recovery force model formula was verified.The basic performance parameters of CRAD-VD main design parameters were analyzed.3、Seismic response analysis of single-degree-of-freedom structure with CRAD-VD: CRAD-VD and visco-damper single-degree-of-freedom vibration control structure models were established respectively,and two comparison models were set for the two structural models: Same model VD,The same displacement target.The dynamic time history analysis program was programmed by MATLAB.When the same VD was selected,the energy dissipation characteristics of the smaller displacement after the displacement and speed amplification effect of CRAD-VD were compared.When the same limit displacement was selected,CRAD-VD force amplification effect and reciprocating displacement characteristics were comparatively studied.Small tonnage and small stroke VD were added to CRAD to achieve the same effect as large tonnage and large stroke VD.Parameters of CRAD design parameters were analyzed and the response spectrum analysis was conducted to explore the influence of CRAD design parameters on the single-degree-of-freedom structure seismic response.4、Seismic response analysis of shear-isolated structure with CRAD-VD:The several fail formation of isolated structure are Summarized,and the necessity of isolated structure in preventing rare earthquakes was expiored.A nonlinear dynamic time-history analysis program for layer shear-isolation structures was compiled using MATLAB.Seismic response and failures of isolated structure under extremely rare earthquakes were evaluated.The CRAD-VD is used as a limiting device attached to the isolation layer.The CRAD-VD limit control effect and mechanical properties are analyzed and compared with the viscous damper VD.By changing the CRAD design parameters to change their magnification,the limit control effect of CRAD-VD and the demand performance of C-VD were studied under the same limit target displacement and different magnification,and the control effect equivalence of the viscous damper VD was analyzed,which was designed for the CRAD-VD.Parameter selection provides a reference.