APPLICATION OF RESPONSE SURFACE METHOD IN SYSTEM RELIABILITY ANALYSIS

A failure mode, which consists of failure elements, is considered as a parallel system. All failure modes form a series system. A structural system is modeled as a series system that consists of failure modes. In the first step, stochastic finite element method based on response surface is suggested to get a set of limit state functions of failure elements of a failure mode. All these functions are quadratic polynomial. In the second step, a set of equivalent linear equations for these functions is obtained by geometric method in structural reliability analysis and an equivalent linear equation of the failure mode is evaluated step by step. In the third step, the correlation coefficients between failure modes are evaluated., structural system reliability is computed by Ditlevsen bounds method. A numerical example shows that the suggested approach is efficient and applicable.