Statistical grain size effects in fretting crack initiation

Abstract

A crystal plasticity computational framework is developed and validated to investigate the microstructure sensitivity of crack initiation in fretting. Randomly distributed microstructure geometries are incorporated into a partial-slip finite element fretting model. The number of cycles to fretting crack initiation is shown to be sensitive to average grain size and microstructure morphology. Scatter in the number of cycles to crack initiation is shown to increase as the number of grains across the contact width decreases due to statistical size effects. Average number of cycles to crack initiation is shown to increase with decreasing number of grains in the contact. Microstructure morphology is shown to have a negligible influence on the effect of stroke for the partial slip cases considered here.