Modeling large strain multiaxial effects in FCC polycrystals

Results from compression, torsion, compression-followed-by-torsion and torsion-followed-by-tension experiments are presented for 304L stainless steel at room temperature. Very distinct stress state-dependent loading compared to uniaxial compression at the same uniaxial equivalent strain. Secondary axial effects are measured during torsional loading as well. Pertinent inelastic deformation processes are discussed and explanations are offered for the observed stress state-dependent phenomena, including morphological changes of both texture and deformation substructure. We review basic micro- and macro-scale model frameworks for modelling large deformation stress-strain behavior. Efforts to capture stress state-dependent phenomena using such formulations are presented. A macro-scale model framework is proposed which uses the third invariant of overstress, J3∗, to delineate stress state effects.