Analysis Of The Optimum Parameters Of The Isolation Layer Of Parallel-composite Isolation System

Parallel-combined isolation is that different types of isolation and energy dissipation devices are combined and parallel layed.It can fully utilize the properties of different devices to achieve the best damping effect.In this paper,four kinds of commonly used parallel-combined isolation systems are analyzed to obtain the optimum parameters of the isolation layer.The main research contents and conclusions are as follows:1.Three typical multi-layer frame structures are selected by Latin hypercube sampling method,then isolate them.The isolation layers are composed of natural rubber(NRB)and lead rubber bearings(LRB),and defined that the lead content is the key parameter.The analysis of damping effect of three isolated structures with various lead contents shows,the best damping effect achieves when the isolation layer composed of NRB and LRB has the range of lead content of 0.104 to 0.236,or the range of ratio of quantity of LRB and NRB is 1:5 to1:2.2.The three structures are isolated with isolation layers composed of LRB,NRB and elastic slide bearings(ESB).The layers and defined that the lead content and pressure ratio are the key parameters.The analysis of damping effect of three isolated structures with various lead contents and pressure ratios shows,the best damping effect achieves when the layer has the range of lead content of 0.312 to 0.426 and pressure ratio of 0.769 to 0.814,that is,the range of ratio of quantity of NRB,LRB and ESB is 1:3:3 to 1:1:5.3.Modify the isolation layers and layers are composed of LRB,NRB and fluid viscous dampers(FVD).The layers and defined that the lead content and the additional damping ratio are the key parameters.The analysis of damping effect of three isolated structures with various lead contents and additional damping ratios shows,the best damping effect achieves when the layer has the range of lead content of 0.134 to 0.269 and additional damping ratio of 14% to 21%.4..Modify the isolation layers and layers are composed of LRB,NRB,ESB and FVD.The layers and defined that the lead content,pressure ratio and the additional damping ratio are the key parameters.The analysis of damping effect of three isolated structures with various lead contents,pressure ratios and additional damping ratios shows,the best damping effect achieves when the layer has the range of lead content of 0.31 to 0.59,pressure ratio of 0.64 to 0.81,and additional damping ratio of 0.7% to5.29%,that is,the range of ratio of quantity of NRB,LRB,ESB and FVD is 1:1:5:4 to1:2:4:6.5.In the consideration of seismic islation effect and the economic costs using optimal layout ratio of the four seismic isolation schemes,the optimal isolation scheme of the isolated structure under different control is obtained.