Abstract:
Model equations were derived from first principles for nonlinear surface wave propagation in a piezoelectric material. There is no dependence on ad hoc or empirical parameters. The present work extends an earlier analysis of surface waves in crystals, described by the authors at the previous meeting [J. Acoust. Soc. Am. 99, 2538(A) (1996)]. As in the earlier work, the model equations account for crystals having arbitrary symmetry, and for surface wave propagation in arbitrary directions in planes having arbitrary orientations with respect to the crystalographic axes. Here, elastic, piezoelectric, dielectric, and electrostrictive properties of the material are taken into account. The model is formulated as spectral evolution equations that are integrated numerically to illustrate the distortion of a finite amplitude surface wave that is sinusoidal at the source. The material we considered is LiNbO[inf 3], for which measured values of all required second- and third-order elastic constants are available in the literature [e.g., the latter are reported by Cho and Yamanouchi, J. Appl. Phys. 61, 875 (1987)]. Analysis of the nonlinearity matrix permits identification of which physical effects contribute most to the distortion of nonlinear surface waves. [Work supported by ONR, NSF, and Schlumberger Foundation.]