Discrete dislocation simulations of the development of a continuum plastic zone ahead of a stationary Mode III crack

Abstract

We present results from discrete dislocation simulations showing the development of the plastic zone in front of a Mode III crack under constant load. We find that the equilibrated zone is circular, in agreement with continuum mechanics predictions of the elastic-perfectly plastic Mode III crack. The size of the equilibrated zone scales as the square of the applied load (KIII), also in agreement with the continuum results. The zone approaches saturation exponentially, with a time that scales as KIII2/σp3, where σp is the Peierls stress. These results delineate conditions under which the classical, continuum predictions of elastic-plastic fracture mechanics are applicable. © 2003 Published by Elsevier Science Ltd.