Plastic Intermediate Configuration and Related Spatial Differential Operators in Micromorphic Plasticity

Abstract

The finite deformation kinematics of micromorphic plasticity is discussed in the framework of multiplicative decomposition of the macro- and microdeformation gradient tensor, suggesting the introduction of a so-called plastic intermediate configuration for the micromorphic continuum. The geometrical structure of the plastic intermediate configuration and the micromorphic curvature tensors are elucidated by invoking the differential operator of the relative covariant derivative with respect to the plastic intermediate configuration. Micromorphic curvature tensors arise in a natural way by considering scalar-valued differences. The latter measure the deformation process and are required to be form-invariant with respect to the chosen configuration.