Structural Reliability Analysis of Marine Diesel Engine Shafting Systems: An Equivalent Stationary Process Approach to the Level Crossing Problem

This paper is concerned with the level crossing problem of a stress above some limit. The problem arises when the structural reliability of a diesel engine shafting system is examined. The first excursion failure probability is derived for the case that the stress on the shaft is a one-frequency cyclostationary random process. A new method is introduced where the cyclostationary random process is replaced with an equivalent stationary one, defined to have an envelope process with the same upcrossing rate as the envelope of the original cyclostationary process. Both processes are assumed to have the same probability of upcrossing a specific threshold. The agreement between this approach, which results in an analytical expression, and the "exact," computationally time-consuming "Markov approach" presented in earlier work is excellent.