Experimental determination of the reversed plastic zone size around fatigue crack using digital image correlation

Abstract

This paper provides an experimental methodology to determine the reversed plastic zone size at the crack tip under cyclic loading through high-resolution DIC measurements. Due to the small size of this region, a 3D-DIC system based on two cameras in a stereoscopic setup with an optical microscope was used in the experimental setup. Fatigue crack growth tests were performed on AISI 1020 steel specimens to evaluate crack tip plasticity. The experimental results obtained with the proposed methodology demonstrate that the reversed plastic zone is a potential parameter to describe the fatigue crack propagation process and related phenomena.