The effect of static electric field on mechanical and dielectric properties of a lead zirconate titanate (PbZrxTi1-xO3) piezoceramic sample driven by an alternating compressive stress has been experimentally investigated by Zhou etal [J. Am. Ceram. Soc. 88, 867 (2005)]. Numerical simulation for this experimental result using two-dimensional four-state Potts model is presented in this article. Upon polarization switching, the dipole in the perovskite cell undergoes 90° rotation, which is in turn associated with the switching of ferroelastic strain state. Consequently, the stress-strain relation and hence the mechanical stiffness are strongly influenced by the magnitude of the dc bias. Optimal mechanical and piezoelectric responses can be obtained by the suitable selection of biasing field.