On generalized crystal-plasticity based on defect-densities in a second-order continuum

Single crystals display various defects that may potentially act as obstacles to further evolution of inelastic deformations, i.e. to further plastic flow. These are translational defects in terms of dislocations, rotational defects in terms of disclinations, and (dilatational) pointdefects in terms of lattice vacancies or interstitial atoms. A formulation of generalized crystalplasticity is proposed that incorporates the densities of these defects in order to capture the hardening of the material. In particular the inclusion of the defect densities other than the dislocation density requires to root the formulation in a second-order continuum description