基于离散小波变换的滑移隔震结构非平稳随机响应计算

NON-STATIONARY EARTHQUAKE RESPONSE ANALYSIS OF SLIDING STRUCTURES BY DISCRETE WAVELET TRANSFORM

将地震地面运动模拟成非平稳随机过程,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稳地震作用下的均方滑动位移和速度反应。通过计算实例与Monte-Carlo法的计算结果进行对比,验证了本文方法的正确性。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。

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. In comparison with the Monte-Carlo method, it is shown that the non-stationary earthquake responses of sliding structures can be calculated correctly by the discrete wavelet-based analysis method. Finally the maximum root mean square slip displacement spectra of the base-isolation structure are presented.