Fuzzy Dynamic Reliability Model of Dependent Series Mechanical Systems

Abstract

Conventional static fuzzy reliability models cannot be directly extended for dynamic reliability analysis of mechanical systems, which consist of correlative components with strength degradation, due to the difficulties in describing the strength degradation process of components under fuzzy load and considering the failure dependence between different components in a system in the possibility context. To deal with these problems, fuzzy dynamic reliability models of mechanical systems in terms of stress and strength are proposed in this paper, which take into account the degradation mechanism of mechanical components in the failure mode of fatigue. The proposed models can be used to represent the dynamic characteristics of fuzzy reliability and analyze the influences of the variation in the parameters of fuzzy stress and strength on the failure dependence of components in a system and the dynamic behavior of fuzzy system reliability. Besides, the explosive bolts for connection between launch vehicle and satellite are chosen as a representative example to illustrate the proposed method. The results show that different parameters of fuzzy stress have different influences on fuzzy system reliability and the failure dependence of components in a system.