Damage mechanics model for the initiation life of stress corrosion cracking

The problem of stress corrosion cracking initiation has been studied on the base of continuum damage mechanics. The attack of load together with environment will weaken the materials, and the degree of the weakening can be described well by the damage variable used in damage mechanics.Just as the use of the damage mechanics in predicting the initiation life for creep and fatigue cracks, a stress-corrosion damage evolvement model , which has considered the roles of the threshold stress , effective stress and the existed damage, is established. And the effects of the environment corrosion are presented with the parameters in the evolvement model. Then a stress-corrosion crack initiation life model is deduced from the damage evolvement model with the concept of the damage accumulation.
The initiation lives of the stress corrosion cracking have been predicted for two kinds of materials at different stress levels .The predicted results show a good agreement with the testing results.