AN ANALYSIS OF LARGE-STRAIN DAMAGE ELASTOPLASTICITY

The elastoplastic constitutive analysis which utilizes the model of multiplicative decomposition of the deformation gradient into its elastic and plastic parts has been mainly developed and applied to elastically isotropic materials, which remain isotropic during the process of plastic deformation. This paper extends the application of the model to materials that change their elastic properties during the deformation process as a result of the material degradation and the corresponding damage. The exact kinematic and kinetic analysis of the finite deformations leads to an additive decomposition of the total strain rate into its elastic, damage and plastic constituents. The general structure of the expression for the damage strain rate is derived, valid for utilized damage tensors of any order. The analysis of elastoplastic deformation of elastically anisotropic materials without damage is also presented, with the application to transversely isotropic materials. The relationships between the elastic and plastic strain rates and the components of the multiplicative decomposition and their rates are also given.