OICC Press Mathematical Analysis and its Contemporary Applications 5 4 2023 10 01 Analysis of a class of frictional contact problem for elastic-viscoplastic piezoelectric thermal materials 10.30495/maca.2023.2007430.1082 EN Ahmed Hamidat Laboratory of Operator Theory and PDE, Foundations and Applications, University of El Oued, Faculty of Exact Sciences, El Oued, 39000, Algeria Journal Article 2023 10 01 We consider a quasistatic frictional contact problem with a subdifferential boundary condition for general thermo-electro-elastic-viscoplastic materials. The frictional contact is modeled by a general velocity-dependent dissipation function. We derive a weak formulation of the system and then prove the existence of a unique weak solution to the problem. The proof is based on arguments of evolutionary variational inequalities, parabolic equations, the variational equation, differential equations, and the fixed-point theorem. Finally, we describe a number of concrete contact and friction conditions to which our results apply.