Fatigue lifetime under stochastic loading with random overloading pulse trains

A mixed, partially numerical, partially analytical approach is used in this paper to determine the lifetime probability distribution of a structural e lement subjected to stochastic loading with overloading pulse trains of ran dom intensity, random duration and random time of occurrences. The analysis is based on two features: Markov property of extremes of stationary stocha stic processes and block structure of the fatigue damage process reflecting the discrete memory marked by successive overloads. A simulation procedure is restricted to simple numerical procedure that provides all necessary pa rameters corresponding with the retardation phases after random single over loading and after random overloading pulses. The approach leads eventually to analytical form of probability distribution of the fatigue lifetime whil e the retardation effects due to compound stochastic loading as well as the random material properties are taken into account. (C) 1999 Elsevier Scien ce S.A. All rights reserved.