Micromechanical modelling of strain path dependency in FCC metals

The analysis of the formability of metals is a traditional topic in mechanical engineering, which is still characterised by many open issues. In spite of many decades of research, this field continues to trigger new challenges, especially promoted by industrial progress. The growing need for more precision in forming processes and the exploitation of more complex manufacturing processes, necessitates a better understanding of the relevant micromechanical processes and the development of more sophisticated engineering tools. The physical origins of the complex deformation behaviour observed for metals, reside, among others, in the textural anisotropy of the material and the anisotropy of the dislocation structures accompanying the plastic deformation. The microscopic deformation mechanisms, associated with the presence and development of these microstructural entities, affect the macroscopical behaviour of a metal, altering its formability. This thesis addresses two major aspects of the formability analysis of metals, both based on the underlying evolving microstructure: (1) the prediction of forming limits and (2) the prediction of strain path change effects. The following sections shortly highlight the challenges in these fields, from which the research scope of the thesis has been derived