滑移隔震结构非平稳随机响应的动力特性分析

基于指数摩擦力模型，利用预估校正的数值积分方法计算滑移隔震结构的动力响应，分析了地面谐振运动下结构的加速度传递率及基底滑移率随频率比的变化规律，并发现滑移隔振结构的振动有振幅跳跃，基底爬行等非线性动力特征。将地震地面运动模拟成非平衡随机过程，基于离散小波变换得到地面运动离散小波系数的统计值，并以此作为输入，使用等价线性方法获得了滑移隔震结构在非平衡地震作用下的均方滑动位移和速度反应。最后，给出了这种结构的最大滑动位移响应随滑移面摩擦系数的变化曲线，可供设计时参考。

Study on Non-stationary Seismic Response Characteristics of Sliding Structures

Based on exponential friction model, seismic responses of sliding structures are investigated by estimating revising numerical integration. The law of acceleration ratio and slippage ratio varied with frequency, ratio under a harmonic base motion is analyzed, it is observed that sliding structures possess non-linear dynamic characteristics such as amplitude jump, base raft climb and so on. A discrete wavelet-based stochastic formulation has been presented in this paper for the seismic analysis of sliding structures. The ground motion has been modeled as a non-stationary process by using discrete wavelet transform. The proposed formulation is based on replacing the non-linear system by an equivalent linear system with time-dependent properties. The expressions of the instantaneous damping, mean square velocity response and slip displacement response have been obtained in terms of the input discrete wavelet coefficients. Finally the maximum root mean square slip displacement spectra of the base-isolation structure are presented.