独立失效模式多自由度随机滞回系统可靠性分析

基于Bouc-Wen滞回模型,研究了由滞回环本身的随机性导致的多自由度非线性随机系统可靠性分析问题。基于结构失效的首次穿越模型,应用四阶矩技术和Edgeworth级数逼近技术,对独立失效模式下多自由度随机滞回系统的可靠性问题进行分析。数值算例表明,由独立随机参数表征的随机结构,系统随机响应之间不再独立,存在协方差;系统响应之间相关系数不唯一,具有随时间连续变化的动态、强相关特性。分析计算结果与Monte-Carlo模拟结果吻合较好,表明算法能够满足工程计算精度要求。

Reliability analysis of MDOF uncertain hysteretic systems with independent failure modes

A numerical method for dynamic reliability analysis of nonlinear random vibration system is presented. Based on the Bouc-Wen hysteretic model and first passage failure criteria, the probability perturbation scheme and the fourth moment method are extended to discuss dynamic reliability assessment of stochastic multi-degree-of-freedom hysteretic system with independent failure modes. Numerical example indicated that system characterized by independent random parameters, the responses were strongly and dynamic correlated. Results obtained by proposed method were agreed with Monte-Carlo simulation very well, which was verified that the presented numerical method could employ for engineering problem with highly accuracy.