A new polycrystalline plasticity model to improve ratchetting strain prediction

International audienceIn this work, a polycrystalline plasticity model is proposed with a new scale transition rule from the macroscopic level to the grain level. The proposed constitutive model intended to improve ratchetting behavior is presented within a thermodynamic framework. Material parameter estimates are obtained through an identification study, where the error is minimized by simultaneous comparison with (i) an aggregate model computed by the FE (finite element) technique and (ii) experimental data taken from the literature. Noticeable improvements for describing experimental ratchetting tests are obtained compared to the β-rule of the Pilvin Cailletaud model [Cailletaud, G., Pilvin, P., 1994. Utilisation de modèles polycristallins pour le calcul par éléments finis. Rev. Eur. Eléments Finis 3, 515–541]