Nanomechanics of Crack Front Mobility

Abstract

Minimum energy paths for unit advancement of a crack front are determined by reaction pathway sampling, thus providing the reaction coordinates for the analysis of crack tip mechanics in ductile and brittle materials. We compare results on activation energy barrier and atomic displacement distributions for an atomically sharp crack in Cu, where one observes the emission of a partial dislocation loop, and in Si, where crack front extension evolves in a kink-like fashion.