Modelling dislocations in a polycrystal using the Generalised Finite Element Method

Modelling the interaction of dislocations with internal boundaries and free surfaces is essential to understanding the effect of microstructure on dislocation motion. However, dislocation dynamics methods rely on infinite domain solutions of dislocation fields which makes modelling of heterogeneous materials difficult. A finite domain dislocation dynamics capability is presented that resolves both the dislocation array and polycrystalline structure in a compatible manner so that free surfaces and material interfaces are easily treated. In this approach the polycrystalline structure is accommodated using the Generalised Finite Element Method (GFEM) (Simone et al., 2006) and the displacement due to dislocations is added to the displacement approximation.