4aPA1. Nonlinear surface wave propagation in crystals.

Session: Thursday Morning, May 16

Time: 8:00

Author: M. F. Hamilton
Author: Yu. A. Il'inskii
Author: E. A. Zabolotskaya
Location: Dept. of Mech. Eng., Univ. of Texas, Austin, TX 78712-1063


Elastic wave propagation along the free surface of a crystal differs from Rayleigh wave propagation in an isotropic solid. In particular, the phase speed and depth dependence vary with the direction of propagation with respect to the crystallographic axes, and the wave-vector component perpendicular to the surface is complex. Results from a theoretical investigation of nonlinear propagation along a free surface of a crystal are presented. The analysis is based on spectral equations that are derived with Hamiltonian formalism. The equations were integrated numerically to illustrate finite-amplitude distortion of a surface wave that is sinusoidal at the source. In one example, calculations based on published material properties are presented for surface wave propagation in KCl out to distances beyond where shock formation occurs. Waveform distortion associated with propagation along the [111] axis in KCl was found to be similar to that of Rayleigh waves in isotropic solids. However, for propagation along the [001] axis in KCl, energy transfer from the fundamental to the second harmonic component is very inefficient, and the waveform distortion was found to differ considerably from that of Rayleigh waves. [Work supported by NSF, ONR, and the Schlumberger Foundation.]

from ASA 131st Meeting, Indianapolis, May 1996