On the Tolerance to Short Cracks under Fatigue and SCC Conditions

The fatigue behavior of mechanically short cracks that depart from notch tips can be mechanically modeled using sound stress analysis techniques which properly account for the notch tip stress gradient influence on their growth rates, considering the basic fatigue properties of the material, its fatigue limit and long crack propagation threshold, and all the characteristics of the notch geometry and of the loading, without the need for any data fitting parameter. This model's predictions have been validated by proper tests, and a criterion to accept tolerable short cracks has been proposed based on it. In this work, this criterion is extended to model notch sensitivity effects in environmentally assisted cracking conditions.