Plastic slip distribution in two-phase laminate microstructures: Dislocation-based versus generalized-continuum approaches |
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Authors: | Samuel Forest Radan Sedláček |
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Affiliation: | 1. Ecole des Mines de Paris (CNRS) , Centre des Matériaux (Unité Mixte de Recherche associée au CNRS 7633) , BP 87, Evry Cedex , 91003 , France;2. Lehrstuhl für Werkstoffkunde und Werkstoffmechanik , Technische Universit?t München , Boltzmannstrasse 15, Garching , 85747 , Germany |
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Abstract: | The size-dependent mechanical response of a simple model microstructure is investigated using continuum dislocation-based, Cosserat and strain-gradient models of crystal plasticity. The governing equations and closed-form analytical solutions for plastic slip and lattice rotation are directly compared. The microstructure consists of a periodic succession of hard (elastic) and soft (elastoplastic single-crystal) layers, subjected to single glide perpendicular to the layers. In the dislocation-based approach, inhomogeneous plastic deformation and lattice rotation are shown to develop in the soft channels, either because of bowing of dislocations or owing to pile-up formation. The generalized continuum non-local models are found to be able to reproduce the plastic slip and lattice rotation distribution. In particular, a correspondence was found between the generalized-continuum results and line tension effects; the additional or higher- order balance equations introduced in the non-local models turn out to be the counterparts of the equilibrium equation for bowed dislocations. The relevance and possible physical interpretation of additional or higher-order interface conditions responsible for the inhomogeneous distribution of plastic slip and lattice rotations are discussed. |
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