Dynamics of a dislocation set in motion by an external stress

The relation between dislocation velocity and resolved shear stress is studied computationally at the atomic scale using Molecular Dynamics simulations in a two-dimensional Lennard-Jones system. Mimicking a well known experimental technique, we apply a calibrated stress pulse to a system with a single dislocation and follow with a run-time graphics tool and displacement-field based tracking method, the dislocation motion caused by momentum transfer from an externally generated stress pulse. The empirically suggested power law relation between dislocation velocity and resolved shear stress seems to hold also in the atomic scale.