The aim of this thesis is to understand and model the ratcheting phenomenon by implementing a full-field numerical simulation approach, using the finite element method, of the mechanical response of polycrystalline aggregates under cyclic loading. In this context, the description of local behavior, at the grain scale, will be based on constitutive equations of crystal plasticity (or visco-plasticity) type, including non-linear isotropic and/or kinematic hardening formulated in terms of dislocation density. Particular attention will bepaid to the description of latent hardening.
This work will involve, among other things, implementing the numerical integration scheme of the local behavior law within the finite element solver used : Abaqus, Zset or Foxtrot (in-house solver) by developing user subroutines or using suitable free libraries (M-Front, https://tfel.sourceforge.net). The implementation of full-field calculations will require the use of parallel computing.
This thesis is aimed at students of a Master's degree in Mechanics and/or Materials and/or Numerical Modeling, who are motivated, rigorous and methodical, with definite taste for numerical simulation and modelling, multi-disciplinary approaches and teamwork.
Some knowledge in c++ programming language and experience in finite element solver (Abaqus, Zset) would be a strong asset.
