Surface waves in electrostrictive materials under biasing fields

The theory of small incremental fields superposed on finite biasing fields in an electroelastic body is summarized first in this paper. The Stroh formalism for two-dimensional anisotropic elasticity and piezoelectricity is generalized to two-dimensional problems of an electroelastic body under biasing mechanical and electric fields. Application of this generalized Stroh formalism to study surface waves propagating in an electroelastic half-space under uniform initial fields indicates that there exist at most two surface waves even in the presence of biasing fields and these two surface waves correspond to the well-known Rayleigh and Bleustein waves in the mechanical nature. A simple procedure is established to distinguish these two types of waves. Application of the results to a model electrostrictive material is included for illustration. It is found that initial biasing fields can greatly influence propagation feature of surface waves.