The energy momentum tensor in the presence of body forces and the Peach–Koehler force on a dislocation

A modified energy momentum tensor, in the presence of body forces, is introduced and used to construct the nonconserved J, M, and L integrals, and to derive the energetic forces associated with a defect motion within the material. The J integral is then applied to evaluate the Peach–Koehler force on an inclined edge dislocation within a large block due to its own weight. The equilibrium position of the dislocation is determined for different boundary conditions of interest in geomechanics.