Fatigue Crack Growth Under Random Overloads with Retardation

A Monte Carlo simulation scheme is presented to study the behavior of fatigue crack propagation under random overloads. Overloads of Poisson flow with uniform distribution on base-line constant-amplitude cyclic loads are considered. The retardation effect of overload on fatigue crack growth is taken into account by using Wheeler retardation model. The fatigue crack growth curve from initial crack size till fatigue fracture is simulated step by step. With the large number of the simulated samples, the average fatigue crack propagation life is obtained and the influences of overload intensity and magnitude on fatigue lifetime are studied.