4aSA12. Backscattering of obliquely incident plane waves by a composite cylindrical shell constructed of isotropic and transversely isotropic layers.

Session: Thursday Morning, May 16

Time: 11:15

Author: Gregory Kaduchak
Author: Charles M. Loeffler
Location: Appl. Res. Labs., Univ. of Texas, P.O. Box 8029, Austin, TX 78713-8029


Acoustic scattering from a transversely isotropic cylindrical shell excited by an obliquely incident plane wave is examined. The shell is comprised of N layers which may be described by isotropic or transversely isotropic material parameters. The present research solves the boundary value problem for a transversely isotropic, infinite cylindrical layer within the framework of exact 3-D elasticity theory. The layers which comprise the shell are connected via a ``propagator matrix'' which relates the interior and exterior boundary conditions. The backscattering form function is then constructed for several commonly used composite materials which display transverse isotropy. The results for anisotropic shells are compared to results found for isotropic shells with similar parameters. Here, attention will be given to the similarities (and dissimilarities) of the scattering mechanisms which are the chief contributors to the backscattering form function as the degree of transverse anisotropy is increased. Analysis of the scattered waveform through Fourier synthesis into the time domain will also be discussed. [Work supported by ONR.]

from ASA 131st Meeting, Indianapolis, May 1996