Bayesian Reliability Analysis for Maintaining Integrity of Aircraft Structures. 2nd Report. Application of Fuzzy-Bayesian Approach.

This paper describes a Fuzzy-Bayesian analysis for deciding a proper inspection schedule to maintain aircraft structural integrity and compares it with the conventional Bayesian analysis developed in the preceding paper. Although subjective information is often given by inspection results because of fuzzy environment which arises from inspectors' judgement, it is difficult to make use of fuzzy information under conventional statistical theories. In the present study, an atempt is made for investigating fuzzy information expressed in terms of linguistic variable and considering a fuzzified Bayes' theorem in order to obtain posterior probability from the information. According to this approach, a priori uncertain parameters are estimated from data collected during in-service inspection. Numerical examples are presented to demonstrate the effectiveness of fuzzy information as well as that of objective one on continuing aircraft structural integrity.