A flexible boundary condition for static dislocations was developed in order to avoid the well-known boundary effect problem. When using this flexible boundary condition, the displacements of atoms in the boundary region were altered as a function of the state of the entire system. The new boundary condition for a moving straight dislocation was obtained by employing Lagrangian principles. As an example, glide motion of the dislocation was simulated in a 2-dimensional lattice by using both flexible and rigid boundary conditions. The results for a system with low Peierls stress and flexible boundary condition were independent of the model size used in the simulation, and were in agreement with the results of a large rigid-boundary model.

Flexible Boundary Condition for Moving Dislocations. K.Ohsawa, E.Kuramoto: Engineering Science Reports of Kyushu University, 1997, 18[4], 317-22