The effect of grain orientation on fretting fatigue plasticity and life prediction

A study on crystal and J2 plasticity prediction of fretting fatigue is presented, using a microstructure-sensitive fatigue parameter for crystal plasticity crack nucleation and a critical-plane (multiaxial) fatigue parameter for J2 plasticity. A short crack propagation methodology is also implemented. The effect of grain orientation on nucleation life is shown to be significant for fretting fatigue. J2 plasticity generally predicts conservative lives. Crystal plasticity is superior in terms of (i) accuracy of life prediction, (ii) ability to facilitate wear prediction and (iii) capturing the key effects of substrate fatigue stress and grain orientation on life. The crystal plasticity model facilitates new insight into interaction between grain orientation, fatigue stress amplitude and fretting surface damage vis-à-vis fretting fatigue life.