对直径为600 mm和1100 mm的铅芯橡胶支座进行了剪切变形400％的水平大变形剪切试验,试验结果表明支座在240％剪切变形后发生屈服后刚度增大现象,且硬化刚度随剪切变形的增大而增大,400％剪切变形时刚度硬化增加到1.5倍.根据试验结果进一步提出了一种考虑硬化效应的铅芯橡胶支座多线性大变形硬化恢复力模型,并将此模型用于Perform-3D软件中.对8层隔震结构进行不同地震烈度下的弹塑性分析,支座分别采用传统双线性模型与多线性大变形硬化模型,对比分析结构的地震动响应、弹塑性反应谱以及塑性耗能情况.结果表明在大震下隔震支座硬化隔震效果减弱,上部结构加速度增加30％ ～ 50％,结构塑形耗能增加,上部结构进入塑性变形状态.研究结果表明隔震设计中大震验算不考虑支座硬化效应会低估结构地震反应.%The horizontal large deformation shear tests with shear deformation 400％ were conducted on LRB600 and LRB1100.It was shown that the bearings' stiffness after yielding increases when their shear deformation reaches 240％,the hardening stiffness increases with increase in shear deformation,the hardened stiffness increases by 1.5-fold when shear deformation reaches 400％.According to the test results,a new multi-linear large deformation hardening restoring force model considering the hardening effect of LRB was proposed.This model was used in the software Perform 3D.The elastic-plastic analysis was performed on an 8-storey structure under different earthquake intensities,the traditional bilinear model and the proposed multi-linear one were adopted,respectively for LRBs to comparatively analyze the structure's seismic responses,elastic-plastic response spectra and plastic energy-dissipation states.The results indicated that the bearing hardening can weaken the seismic isolation effect of LRBs under the major earthquake,the acceleration of the upper structure increases by 30％ ～ 50％,the structure's plastic energy-dissipation increases,the upper structure enters the plastic deformation status;so,the seismic response of the structure may be underestimated without considering the bearing hardening effect in the seismic isolation design.
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