Modeling of evolving anisotropy at finite elasto-plastic strain

Simulation tools are used to a wide extent in the product development process today, both to obtain better products and to reduce the development time required. Anisotropic materials are utilized in many engineering applications. Material models for materials of these types are needed in order to obtain accurate results from the simulations undertaken. In the thesis, a constitutive framework for anisotropic materials at finite elasto-plastic strains is presented. The general framework used for the modeling of anisotropic materials is discussed in Paper A. Here the kinematics of anisotropic materials being analyzed with the aim of developing a general description. Thermodynamical considerations are taken into account to assure that the dissipation inequality is not violated. Some simple numerical examples are also studied. In Paper B the proposed model is investigated further and a formulation based on a spatial setting is developed. Here the numerical formulation is discussed and the model is implemented into the commercial finite element code ABAQUS. Two numerical examples are investigated to explore the capabilities of the model. One involving the deformation of a plate with a hole and the other the drawing process of a cup