Modèle physique de la plasticité d'un cristal métallique CFC soumis à des chargements alternés :
Contribution à la définition d'une modélisation multiéchelles de la mise en forme des métaux.

摘要

This work is realised in the perspective to contribute to the development of physical based models of plastic deformation that are intended to be used in numerical simulations of FCC metals forming operations. In this purpose, we propose a micromechanical modelling making use of micro structural variables such as dislocation densities and their distributions on each slip system. Physical models of isotropic and kinematics work hardening are proposed in order to simulate alternated (cyclic) loads. In addition to define particular model of metal behaviour, this work presents various steps that lead to use it in a macroscopic numerical simulation. This consists in the definition of experimental procedure which provides necessary data to validate the model. This experimental procedure makes use of Digital Image Correlation (DIC) and Infrared (IR) images processing to measure simultaneously heterogeneous displacements and temperature fields at the samples surface. Physical based model is then implemented in a commercial finite element code “ABAQUS” in order to simulate complex boundary conditions which can be found in metal forming operation. In spite of the fact that the modelling of such boundary conditions is not realised in this work, this model presents high potential to make it.