Wave propagation in electrostrictive materials under biasing fields

Constitutive relations for nonlinear, isotropic, electroelastic solids quadratic in the finite strain tensor and the reference electric field are derived from the fully nonlinear theory of electroelasticity by tensor invariants, which can describe the behavior of electrostrictive materials. The equations are linearized for small, dynamic fields superposed on finite, static biasing fields. These linear equations are used to study plane waves propagating in an electroelastic body under various mechanical and/or electric biasing fields. It is shown that the speeds of the acoustic waves exhibit a strong dependence upon those material parameters in the nonlinear constitutive relations. Experimental determination of these material parameters using this dependence is discussed.