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

2aSA4. Acoustic scattering from a fluid-loaded elastic plate with a distributed mass inhomogeneity.

J. M. Cuschieri

Ctr. for Acoust. and Vib., Dept. of Ocean Eng., Florida Atlantic Univ., Boca Raton, FL 33431

D. Feit

David Taylor Research Center, Bethesda, MD 20084

The scattering of a plane acoustic wave by a fluid-loaded, thin, elastic plate, of infinite extent, with a distributed inhomogeneity is investigated by solving the equation of motion in the wave-number domain using the hybrid numerical analytical approach [J. Acoust. Soc. Am. 95, 1998--2005 (1994)]. The presence of the distributed inhomogeneity in the equation of motion, when expressed in the wave-number domain, results in a Fredholm integral equation of the third kind. By substituting for the product of the response and the plate characteristic equation, the Fredholm integral of the third kind is reduced to a Fredholm integral of the second kind. The plate response in the wave-number domain is obtained from the solution of the Fredholm integral. Inverse Fourier transforming the wave-number domain response function gives the spatial domain solution for the response. The hybrid approach is used to perform the inverse Fourier transform. The scattered pressure is obtained in a similar manner. Response and scattered pressure results for distributed mass inhomogeneities, with different distribution functions, are presented and compared to the results for a line inhomogeneity. [Work sponsored by ONR.]