针对地震动复杂频谱特性对隔震结构响应及损伤影响进行研究，用加速度反应谱平均周期 Tr表征地震动周期特性，用 Bouc-Wen 模型及刚度退化的 Bouc-Wen 模型分别描述隔震层与上部楼层的滞变特性，建立隔震结构的质点系非线性分析模型，考虑隔震支座压剪相关性与拉压性能差异建立隔震体系损伤指数模型，分析不同地震动输入加速度幅值及不同 Tr与对隔震结构地震反应、损伤影响规律。分析表明，在地震动高频范围内隔震结构响应随输入加速度峰值增加而增加，但对长周期地震动，输入加速度峰值对隔震结构地震反应影响较小，地震反应呈较大离散性、无规律性；在相同加速度幅值输入下隔震层地震反应、损伤的离散性远大于上部结构，在共振区内虽出现最大地震反应，但也会出现较小地震反应，表明隔震结构瞬时共振为非常复杂的过程。研究可为揭示地震动特性与隔震结构地震反应及损伤的关联性提供分析依据。%The nonlinear characteristics of a base isolated structure and the time-variation of excitation frequency on it make the effect of earthquake ground motion on structural responses and damages very complicated.The average period Tr of response spectrum was used to represent the cyclical nature of earthquake ground motion.The base isolated structure was simplified to a two-mass model,and the Bouc-Wen model and the stiffness degradation of Bouc-Wen model were used to simulate the hysteresis of isolation story and superstructure respectively.Referring to the Park-Ang damage index model and considering the compression-shear correlation and tension-compression difference of isolators,the damage index model of the isolated structure was established.The nonlinear seismic responses and damages of the structure under earthquake ground motion with different Tr were analyzed.The results show that the seismic response and damage both increase with the increase of acceleration peak of seismic wave in the range of high frequency,but the seismic response is of discreteness and irregularity under long period seismic wave.The discreteness of seismic response of isolation layer is larger than that of sup-structure.In resonance region,there may appear the highest seismic response,but it is also possible to see a rather lower seimic response,which indicates that the instantaneous resonance of isolated structure is a complex phenomenon. The study reveals the characteristics of earthquake ground motion and the resulted seismic responses and damages of base isolated structures.
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