【摘要】 在结构动力学系统的可靠性分析中,受随机激励线性系统的首次穿越问题一直是研究热点之一。该文给出了非平稳地震作用下线性系统首次穿越的重要抽样法。应用Gisranov定理变换概率测度,利用设计点构造控制函数,应用到系统的Ito随机微分方程中。通过数值模拟,结果显示了方法的正确性与有效性。与蒙特卡罗模拟方法相比较,样本数量、计算时间都明显减小。更多还原

【Abstract】 In the reliability analysis of dynamical systems subjected to uncertain excitations,the first passage failure is the most important issue.This paper suggests a procedure for estimating failure probabilities of linear systems subjected to a non-stationary earthquake based on importance sampling technique.By using of Gisranov Theorem,the probability measure of Wiener processes is transformed and a control function is constructed.The simulation results show that the method is correct and effective.The number of samples and the computational time are reduced significantly,compared with direct Monte Carlo simulations.更多还原