Interfaces, Confinement, Matériaux et Nanostructures - ICMN

Site web du laboratoire ICMN - UMR7374

Accueil > Evénement > Séminaires

Jeudi 7 Février 2013

14h Salle du Conseil - Bâtiment OSUC

“Micromorphic Crystal Plasticity”

Dr Samuel Forest, Directeur de Recherche CNRS à l’école des mines de Paris

Résumé : The effect of the dislocation density tensor is introduced into the classical crystal plasticity framework by means of the micromorphic theory of single crystals. The micromorphic elastoviscoplasticity theory is presented at finite deformation and applied to the case of single crystals [1]. 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 [2].

[1] N.M. Cordero, A. Gaubert, S. Forest, E.P. Busso, F. Gallerneau and S. Kruch, Size effects in generalised continuum crystal plasticity for two-phase laminates, Journal of the Mechanics and Physics of Solids, vol. 58, pp. 1963-1994, 2010.
[2] N.M. Cordero, S. Forest, E.P. Busso, Generalised continuum modelling of grain size effects in polycrystals , Comptes-Rendus Mécanique, vol. 340, pp. 261-274, 2012.