ON THE MECHANICS OF LARGE INELASTIC DEFORMATIONS - NONCOAXIALITY, AXIAL EFFECTS IN TORSION AND LOCALIZATION

The macroscopic behavior of materials subjected to large deformations is investigated by considering the structure and mechanics of the single slip. Physically based constitutive relations for the plastic flow and material spin are then rigorously derived by resorting to the concept of noncoaxiality; yielding a class of vertex-type plasticity models incorporating features like noncoaxiality and large material rotation. It is shown that these phenomena are inherently coupled through the concept of plastic spin as it relates to the persistence of noncoaxiality. The implication of such phenomena to large deformations is investigated by examing their influence on the development of axial effects accompanying finite shear deformation, as well as on the onset of localized shear bands.