Abstract: In order to estimate the statistical variability of the fatigue crack growth,a stochastic model for fatigue crack growth is proposed by means of combining stochastic theory with exper-imental results. A stochastic differential equation is derived from the stochastic model for fatigue crack growth, By using the solution of the stochastic differential equation, some distribution functions related to the fatigue crack growth are derived. Sample function of fatigue crack growth time histories is simulated as random process.

Key words: fatigue(materials), fatigue life-crack propagation, statistical distribution