【摘要】 人工地震动时程的模拟是结构抗震分析的热点问题。基于平稳离散小波变换理论,利用小波变换的带通滤波特性,推导了各频带小波系数与功率谱密度函数的关系,从而直接采用时变功率谱密度函数,在不同频带上随机生成小波系数,进而通过小波逆变换模拟出同时具有强度非平稳和频率非平稳的地震动时程。对模拟时程的统计特性与目标值进行了比较,证明了该方法的可行性和正确性。更多还原

【Abstract】 Simulation of earthquake ground motion is a hot topic for seismic response analysis of structures.Utilizing the band pass character of wavelet transform,the relations between wavelet coefficients and power spectral density on different frequency bands are deduced based on discrete stationary wavelet transform.Then the random wavelet coefficients of each scale are obtained from the known time-dependent power spectral density function directly.At last,the inverse discrete stationary wavelet transform is applied to generate earthquake ground motion histories which have the properties of nonstationary in both amplitude and frequency contents.Through an example,the statistic characteristics of simulated time histories are compared with the objective values,and the feasibility and correctness of presented method are illustrated.更多还原