Moment method for global sensitivity analysis in multiple failure modes

For reliability model with multiple failure modes commonly used in engineering practice, the moment method is proposed for analysis of the global effect of the basic random variable in case of the multiple failure modes. In the proposed method, fourth-order moment method is combined with the Edgeworth expansion for approximating the probability distribution of the response performance function of the multiple failure modes effectively, which provides a simple and efficient method for solving the conditional and unconditional probability density functions of the response performance function. Several examples are used to demonstrate the rationality and feasibility of the method.