A reduced micromorphic single crystal plasticitymodel to study localization and void growth inductile metals

C. Ling (1) , S. Forest (2) , J. Besson , B. Tanguy (1, 2) , F. Latourte (3)

1 CEA-DES (ex-DEN) - CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire)
2 CDM - Centre des Matériaux
3 EDF - EDF

A micromorphic single crystal plasticity model is formulated at nite deformations asan extension of Mandel's classical theory based on a multiplicative decomposition of thedeformation gradient. It involves a single microslip degree of freedom in addition to the usualdisplacement components. One of the proposed formulation which relies on a Lagrangianmicroslip gradient and leads to a Laplace term in the isotropic hardening law, is implementedin a 3D element code. The model is applied first to strain localization phenomena ina single crystal in tension undergoing single slip. The regularization power of the model isillustrated by mesh-independent simulations of the competition between kink and slip bands.The model is then used to investigate void growth and coalescence in FCC single crystals.Cylindrical and spherical voids are considered successively. The simulations show, for the first time in the case of spherical voids embedded in a single crystal matrix, that smallervoids grow slower than bigger ones, and that the onset of void coalescence is delayed forsmaller voids.

Mots clés: Micromorphic model; Strain gradient plasticity; Ductile single Crystal; Regularization; Void growth; Size effect

Domaines: Physique Nucléaire Expérimentale [nucl-ex]; Physique Nucléaire Théorique [nucl-th]

C. Ling, S. Forest, J. Besson, B. Tanguy, F. Latourte. A reduced micromorphic single crystal plasticitymodel to study localization and void growth inductile metals. 16th Edition of the European Mechanics of Material conference, Mar 2018, Nantes, France. ⟨cea-02339062⟩