Formulation d'un modele constitutif incluant les effets des transformations microstructurales (French text, aluminum)

Computer simulations of manufacturing processes (also refers as "Virtual Manufacturing") are a tools that allows industries to improve their processes and to reduce their costs without having to rely on expensive trial-and-error iterations on their production lines. For the metal forming industry, it is now necessary that computer simulations model correctly the evolution of the materials during of fabrication processes since in addition to the macrostructure (the geometry) of the product, the bulk microstructure and residual stresses evolve during processing and are important to the final customer. The aim of this project was to develop a framework and a model that describes correctly the material mechanical response and allows the tracking of material's state. Thus, a new unified elasto-viscoplastic formulation was developed based on already sound existing physical models. The formulation distinguishes itself from current models by the elimination of the dynamic softening term found in the internal variables evolutionary laws. The model is such that the determination of the parameters is simple because each parameter comes from fundamental well-established physics. The model was implemented into a 3D fully updated lagrangian finite element code (ABAQUS). (Abstract shortened by UMI.)...