载荷相关结构系统的可靠性分析

Reliability Analysis on Structral Systems with Load Dependency

以失效相关性为主要研究对象,阐述共因载荷与元件强度的随机特性对元件失效相关程度、元件联合失效及联合可靠概率之间的影响,揭示元件强度统计独立时由系统共因载荷引发元件失效相关的基本规律。针对载荷全相关、强度独立同分布的并联、串联、表决系统,分析元件失效相关对系统可靠度计算的影响,同时提出载荷全相关结构系统可靠度求解的新方法。得出元件安全裕度随机变量协方差矩阵后,通过正交化方法简化系统可靠度计算,该方法有利于为载荷相关结构系统可靠性设计及优化提供更为全面的参考信息。

In the light of components failure dependency in structural systems, effect s of the common load and components strengths stochastic characteristics upon components failure dependency are described. And the mechanism of the common load giving rise to elements failure dependency whereas strengths of components are independent is studied. For parallel, series and r-out-of-n systems made up of identically distributed components with total load dependency, a feasible approach to system reliability estimation considering failure dependency due to the common environment load is developS. By means of orthonormalization of variables, the calculation can be simplified when the covariance matrix of safety margin variables is figured out, which can give more valuable information to reliability design and optimization.