Reliability Assessment of Mechanical Components Using Fuzzy-Set Theory

An approach to assessing the reliability of mechanical components, especially for pressure vessels and piping, is proposed in which the vagueness and fuzziness in variables have been considered. In this method, a fuzzy-random reliability model is developed by using a fuzzy-set theory. This particular theory can be described as a generalization of the classical set theory. Using a fuzzy-set theory, a failure event is defined in a more flexible form than usual. In particular, the concept of nonfuzzy probability of fuzzy events is used to derive a reliability approach which includes the subjectivity of human judgement. Meanwhile, a constructive way for generating a membership function of a fuzzy set is also provided in the paper.