Efficient numerical algorithm of profust reliability analysis: An application to wing box structure

In aerospace engineering, the reliability analysis technique attracts increasing attention from many structure designers. Compared with the conventional reliability analysis, the probability and fuzzy state assumption (profust) reliability analysis is proposed as a more comprehensive and objective theory to evaluate the structural safety. Because of great computational burden of the existing methods in estimating profust failure probability, an efficient numerical algorithm is developed in this paper. The proposed method is based on an equivalent transformation of the profust failure probability, then the profust failure probability can be rewritten as the form of a series of conventional failure probabilities which have similar constructions. The subset simulation method is employed to compute all the conventional failure probabilities by using a set of samples repeatedly. Next, this method is applied to estimate the profust failure probability of a wing box structure. The calculation results indicate that the proposed method can reduce the computational cost dramatically with acceptable precision.