非线性随机地震响应的概率密度演化分析

Probability Density Evolution Analysis for Stochastic Seismic Response of Nonlinear Structures

强烈地震作用下的结构非线性随机动力响应分析对准确把握结构的安全性和所需的其他性态指标是至关重要的,但在经典随机振动和随机结构分析的理论框架下至今存在难以逾越的巨大困难。结合概率密度演化理论和基于频率优选的随机地震动谱表达模型,成功地实现了随机地震动激励下多自由度结构非线性随机地震响应分析。文中给出了基本理论和数值方法,并以9层框架结构为实例讨论了分析结果。指出了需要进一步研究的问题。

Stochastic seismic response analysis of nonlinear structures is of paramount importance to precisely capture the safety and other required performance indices.However,this cannot be realized as yet because of the great difficulty lying in the classical framework of random vibration and stochastic structural analysis.Incorporating the probability density evolution method with the spectral representation of ground motion based on optimally selected frequencies,stochastic seismic response analysis of multi-degree-of-freedom linear/nonlinear structures is carried out.Fundamental theory and numerical algorithm are outlined.A 9-story structure is taken as an example to illustrate the procedure and results.Problems open are discussed.