Analysis of a dynamic viscoelastic-viscoplastic piezoelectric contact problem Marco Campo, Jose R. Fernández, Ángel D. Rodríguez-Arós and José M. Rodríguez ESAIM: M2AN, 51 2 (2017) 565-586 Published online: 20 February 2017 DOI: 10.1051/m2an/2016027