Local rules for approximating strong dislocation interactions in discrete dislocation dynamics

We consider the problem of approximating the strong dislocation interactions which occasionally take place during the numerical simulation of dense dislocation systems. Local rules are proposed to govern the behaviour of those tracking points that find themselves in an under-resolved environment. It is shown that these rules, utilizing only nearest-neighbour information, satisfactorily approximate more fully resolved calculations of localized dislocation-dislocation interactions, of extended structures such as junctions, and of higher order processes such as dislocation-junction and junction-junction interactions. Use of these rules should make it possible to do efficient large-scale numerical dislocation simulations, while still retaining the important qualitative effects arising from strong local interactions.