Limiting configuration in dislocation glide through a random array of point obstacles

Abstract

We consider a dislocation in glide through a random array of point obstacles. Several important phenomena, including the critical resolved shear stress at zero temperature and the velocity of thermally activated glide at low temperature or at stress near the critical resolved shear stress, are known to be strongly influenced by the properties of the most stable obstacle configuration encountered by the dislocatton during glide. We devise a limiting technique to estimate the mechanical strength, the distribution of forces, and the mean dislocation segment length in this configuration. The estimates are in good agreement with results