The probabilistic prediction of the fatigue crack propagation life of a semi-elliptical surface crack

Safety evaluation of the mechanical components with crack-like defects could be treated probabilistically, because the initial size of defects and other parameters are nondeterministic. In case of an actual structure, such as a pressure vessel, the most important defect is the surface flaw. Since the aspect ratio of a crack may change gradually as the crack grows, the life prediction involving surface flaws is not simple. This paper not only presents a method of probabilistic life prediction for the fatigue crack propagation of semi-elliptical surface crack, but also discuss the effects several parameters for the crack propagation life