Finite strain elastoplastic behavior of uniform bodies based on micropolar theory

Based on micropolar theory, we develop a novel mathematical framework for modeling finite elastoplastic deformations. The proposed formulation accommodates both large strains and finite rotations while exploiting the ability of micropolar theory to represent underlying material microstructure. The balance equations are obtained from an invariance principle with respect to general observer transformations. Within the setting of material uniformity, the plastic evolution laws are expressed as first-order differential equations for a set of material transplants, subject to the formal restrictions dictated by micropolar material symmetries and the constraints of the second law of thermodynamics. In addition, we identify the micropolar Mandel stress tensors as the energetic driving forces governing the local rearrangement of material inhomogeneities.