关键词: 机械学, 结构系统, 可靠性, 对称元件, 失效相关, Copula

Abstract: Copula is a new tool of statistical analysis, by which the probabilistic models for the multiple random vector can be built in terms of flexible expression, and by which the complex feature of statistcal dependence of random variables can be depicted. Copula is introduced in the reliability analysis of structural system. Copula-based method is put forward for the reliability modeling of structural systems composed of identical components. According to the failure-dependence mechanism of components, the modeling steps based on Gauss Copula and Archimedean Copulas are discussed by taking the twin stress and components strength as the basic variables and the safety margins as the analytic variables. Compared with Gauss Copula, Archimedean Copulas has a powerful capability to describe the failure-dependence mechanism since it can determine the adjustable parameters from the rank correlation coefficient and the information about the critical failure point. Archimedean Copula-based reliability models are applicable to non-normal situations. A numerical example shows that the new method is reasonable and feasible. Copula-based reliability model provides a new way for reliability assessment and reliability-based design of complex electromechanical equipment systems with failure-dependence.

Key words: mechanics, structural system, reliability, identical component, failure dependence, Copula