System reliability updating of fatigue-induced sequential failures through inspection and repair

Abstract

The reliability of a structure subjected to fatigue-induced sequential failures can be sustained through structural maintenance as well as structural design. For effective structural maintenance, it is essential to estimate the impact of inspection and repair on structural reliability. This paper proposes a new system reliability updating method through inspection and repair. The proposed updating method identifies critical system failure and non-failure cases by the Branch-and-Bound method employing system reliability Bounds (termed the B3 method), and then update their probabilities based on the observations and actions made during structural inspection and repair. The upper and lower bounds on system failure probability of a structure are updated accordingly. The proposed method is applied to a numerical example of an aircraft longeron system. In the example, various scenarios of inspection and repair are assumed, and the corresponding analysis results from the proposed method are presented. The results show that the method can update system reliability of structures subjected to fatigue-induced sequential failures effectively based on the results of inspection and repair.