Accounting for elastic anisotropy in crystal plasticity within the context of olivine dynamic recrystallization using a level-set framework

Description

Because olivine is the major constituent of upper mantle rocks, its mechanical properties and microstructural evolutions play an important role in the lithosphere rheology. In this study, we investigate the deformation of olivine polycrystals through a numerical framework coupling the crystal plasticity and the finite element method (CPFEM). The rheology of the olivine aggregate is described through a crystal plasticity model that we have developed and that takes into account the elastic anisotropy of the olivine crystal, based on published experimental data. The velocity pressure finite element formulation has also been modfied in order to take into account the informations coming from crystal plasticity computation. In addition to predicting polycrystal mechanical behaviour, this methodology also allows to track the development of lattice preferred orientation (LPO) during deformation. These important features are predicted using the proposed approach during the deformation of olivine aggregate with and without accounting for elastic anisotropy. Our results suggest that the elastic anisotropy exerts a weak influence on the subsequent plastic deformation and thus on polycrystal mechanical behaviour, LPO development and local pressure and stress.

Abstract

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