Saddlepoint approximation of structural reliability on weighted linear response surface method

Based on saddlepoint approximation for structural reliability, a new reliability analysis method is presented for the structure with non normal variables. In the presented method, the limit state function is firstly linearized by the weighted linear response surface method, and the saddlepoint approximation is employed to obtain the cumulative distribution function(CDF) and the probability density function(PDF) of the structural limit state function, then the reliability can be analyzed. The reasonable weight is investigated for the weighted linear response surface method in case of the non-normal variables. After the procedure of the presented reliability analysis is given in detail, numerical and engineering examples illustrate the feasibility and the efficiency of the presented method.