Lattice-based J integral for a steadily moving dislocation

Abstract

According to continuum theory and the conservation theorem, the J integral represents the net translational force acting on a defect and, specifically, it is equivalent to the Peach-Koehler force for dislocation. In this study, we newly derive the J integral to quantify driving force on a uniformly moving dislocation with considering its core-induced dynamic behaviors. Using both molecular dynamics simulation and lattice dynamics theory based on atomic chain model, we prove that radiation drag and self-stress asymmetry during the dislocation motion, which are generated by lattice discreteness, make the newly derived J integral depend on the distance from the dislocation core, which is lumped into resistance to the dislocation motion. Finally, we show that the J integral converges to the Peach-Koehler force as the resistance term disappears for a stationary dislocation.