Root finding method of failure credibility for fuzzy safety analysis

In order to measure structural safety with fuzzy uncertainty, a new root finding method of failure credibility is presented by taking advantage of the simple relation on input and output credibility inverse distributions. A brief introduction is given of the fuzzy credibility measure and the credibility inverse distribution at first. As the theoretical basis of root finding method, principles of transformation from failure credibility solving into a root finding process through credibility inverse distribution functions, are fully explained from the standpoint of root screening conditions as well as computing features. After organizing the fuzzy root finding algorithm for both explicit and implicit performance functions, arithmetical differences of fuzzy safety are meanwhile compared to random reliability to reveal the essence of their different type of uncertainty. Finally the applicability and effectiveness of fuzzy root finding method are testified by several engineering cases.