Variational principles in the theory of gradient plasticity

Gradient models have been intensively discussed in the literature for the study of time-dependent or time-independent processes such as visco-plasticity, plasticity and damage. This Note is devoted to the theory of Gradient Plasticity. A general and consistent mathematical description available for common time-independent behavior is presented. Our attention is focused on the derivation of general results such as the description of the governing equations for the global response, for the rate response, the expression of the associated variational principles and the question of uniqueness in terms of the energy potential and the dissipation potential.