### ASA 128th Meeting - Austin, Texas - 1994 Nov 28 .. Dec 02

## 5aPA10. Leaky Rayleigh wave scattering from elastic media with
microstructure.

**Yuan Zhang
**

**
Richard L. Weaver
**

**
**
*Dept. of Theor. and Appl. Mech., Univ. of Illinois, 216 Talbot Lab., 104
S. Wright St., Urbana, IL 61801
*

*
*
Scattering of leaky Rayleigh wave from a flat fluid--solid interface is
studied. The fluid half-space is taken to be ideal and homogeneous while the
solid half-space has randomly inhomogeneous anisotropic elastic constants due
to the microstructure of the material. For plane waves incident from the fluid
onto the interface at the critical Rayleigh angle, the singly scattered
incoherent field is obtained by utilizing a first Born approximation. When the
solid is a crystal aggregate and when the correlation function is of
exponential form, the mean-square scattered signal level is found to be
inversely proportional to the dimensionless frequency in the high-frequency
limit but proportional to the third power of frequency in the low-frequency
limit. Numerical results are given for water--aluminum interface scattering.
[Work supported by NSF.]