Computation of structural system reliability with hybrid uncertainty of fuzzy variables and random variables

Hybrid uncertainty reliability analysis is an important part in structural reliability analysis. The comparisons of several various transformations of the fuzzy variables to equivalent random variables are drawn. The formula of the transformation of fuzzy variables to random variables is proposed and applied to the computation of structural reliability with hybrid uncertainty. Specific formulas of the equivalent PDFs (probability distribution functions) and their numerical characteristics are obtained, such as the linear membership function and the normal membership function. The compatibility of fuzzy reliability and random reliability is proved by means of the transformations. And probabilistic measurement of hybrid uncertain structural system is reasonable. The reliability computation with hybrid uncertainty is illustrated with an example for comparative study on the consistency of the transformations. The results show that those methods are all effective and consistent.