Composition duality principles for mixed variational inequalities

Primal and dual composition duality principles for mixed variational inequalities in reflexive Banach spaces are established, and applications to macro-hybrid, three-field, and preconditioned augmented variational formulations are discussed. In particular, generalized boundary value problems, potential cases, as well as finite-element approximations and related penalty-duality algorithms are considered. Also, a specific primal and dual mixed model from mechanics, is presented.