Solutions to simple boundary value problems using discrete dislocation plasticity exhibited key features associated with an accumulation of geometrically necessary dislocations: size effects and long-range stresses. Comparisons of the predictions of non-local plasticity theories with the discrete dislocation results provided an assessment of the strengths and weaknesses of various phenomenological theories and also provided a means of identifying appropriate non-local boundary conditions.

GNDs in Non-Local Plasticity Theories - Lessons from Discrete Dislocation Simulations. E.Van der Giessen, A.Needleman: Scripta Materialia, 2003, 48[2], 127-32