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Continuum dislocation dynamics: Towards a physical theory of crystal plasticity

: Hochrainer, T.; Sandfeld, S.; Zaiser, M.; Gumbsch, P.


Journal of the Mechanics and Physics of Solids 63 (2014), S.167-178
ISSN: 0022-5096
Deutsche Forschungsgemeinschaft DFG
Deutsche Forschungsgemeinschaft DFG
Fraunhofer IWM ()
dislocations; crystal plasticity; size effects; mechanical annealing

The plastic deformation of metals is the result of the motion and interaction of dislocations, line defects of the crystalline structure. Continuum models of plasticity, however, remain largely phenomenological to date, usually do not consider dislocation motion, and fail when materials behavior becomes size dependent. In this work we present a novel plasticity theory based on systematic physical averages of the kinematics and dynamics of dislocation systems. We demonstrate that this theory can predict microstructure evolution and size effects in accordance with experiments and discrete dislocation simulations. The theory is based on only four internal variables per slip system and features physical boundary conditions, dislocation pile ups, dislocation curvature, dislocation multiplication and dislocation loss. The presented theory therefore marks a major step towards a physically based theory of crystal plasticity.