Experimental evaluation of plastic wake on growing fatigue cracks from the analysis of residual displacement fields

A growing fatigue crack gives rise to a plastically deformed wake of material that envelops the crack. In this work, plastic extent during growth is experimentally quantified by analyzing tip displacement fields measured with digital image correlation. novel technique based on use yield criterion proposed uses undamaged state specimen as reference in processing. The was identified differentiation residual obtained near-zero load level avoid any rigid body motion. then found assuming boundary between elastic and regions would occur when equivalent stress higher than material. results presented can contribute better understanding mechanisms driving propagation.