Stochastic approach to modeling fatigue crack growth

An extensive set of fatigue crack growth (FCG) data known as the Virkler data is employed to investigate a recently developed stochastic FCG model that is based on concepts from both fracture mechanics and random process theory. The model represents the crack state as a two-dimensional vectored Markov process and, as a result, has eliminated many objections to previous stochastic FCG models. Two FCG laws are considered for use in the stochastic analysis and a modified finite-integral method (MFI) that does not require differentiation of the FCG data is suggested for determining the parameters of the stochastic FCG model. Excellent comparison between theoretical results and experimental data is obtained for all cases considered.