The effect of the dislocation density tensor is introduced into the classical crystal plasticity framework by means of the micromorphic theory of single crystals. A computational homogenisation strategy is presented in order to describe the global and local responses of two-dimensional polycrystalline aggregates for grain sizes ranging from 1 to 200 microns. The model is shown to naturally predict a size-dependent kinematic hardening behaviour which is responsible for the observed strong size effects. The yield stress at a given averaged plastic strain is shown to follow a power law scaling relation for grain sizes larger than a critical one. The field of plastic deformation is also strongly affected by grain size, whereby micron-size grains lead to the formation of intense slip bands crossing several grains.

Nicolas M. Cordero ^{1};
Samuel Forest ^{1};
Esteban P. Busso ^{1}

@article{CRMECA_2012__340_4-5_261_0, author = {Nicolas M. Cordero and Samuel Forest and Esteban P. Busso}, title = {Generalised continuum modelling of grain size effects in polycrystals}, journal = {Comptes Rendus. M\'ecanique}, pages = {261--274}, publisher = {Elsevier}, volume = {340}, number = {4-5}, year = {2012}, doi = {10.1016/j.crme.2012.02.009}, language = {en}, }

TY - JOUR AU - Nicolas M. Cordero AU - Samuel Forest AU - Esteban P. Busso TI - Generalised continuum modelling of grain size effects in polycrystals JO - Comptes Rendus. Mécanique PY - 2012 SP - 261 EP - 274 VL - 340 IS - 4-5 PB - Elsevier DO - 10.1016/j.crme.2012.02.009 LA - en ID - CRMECA_2012__340_4-5_261_0 ER -

Nicolas M. Cordero; Samuel Forest; Esteban P. Busso. Generalised continuum modelling of grain size effects in polycrystals. Comptes Rendus. Mécanique, Volume 340 (2012) no. 4-5, pp. 261-274. doi : 10.1016/j.crme.2012.02.009. https://comptes-rendus.academie-sciences.fr/mecanique/articles/10.1016/j.crme.2012.02.009/

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