Reliably Evaluation Method Considering FM Dependency via Uncertainty Theory

The dependence of failure mechanisms indicates that system failure initiates from dependent failure mechanisms. One failure mechanism developing to a certain degree will trigger, accelerate or inhibit another or many other failure mechanisms and some kind of failure mechanisms may have the same effect on the failure site, component or system. Because of the uncertainty of these correlations of failure mechanisms, it is difficult to predict the degradation process of system and evaluate the reliability of complex system with correlations of failure mechanisms. This paper introduces the uncertainty theory to model the degradation process of failure for the epistemic uncertainty. The geometric Liu process is used to describe the degradation process. Different failure time models are built for different correlations of failure mechanisms and corresponding belief reliability distributions are derived. Some numerical cases are designed to verify these models.