Cyclic Plastic Response and Fatigue Life of Materials

Abstract

Recently the decisive role of plastic strain amplitude for the initiation and the growth rate of short cracks has been demonstrated. The plastic strain amplitude can be related to the rate of short crack growth and also to the fatigue life. Since the cyclic stress-strain response of a material determines the plastic strain amplitude it influences basically its fatigue life. The experiments in stress and plastic strain controlled loading and short crack growth are presented and used to demonstrate the importance of the cyclic plastic response for the evaluation of the fatigue life.