## 2aPAb8. Scattering of an obliquely incident wave by a transversely isotropic cylinder.

### Session: Tuesday Morning, May 14

### Time: 10:30

**Author: Farhang Honarvar**

**Author: Anthony N. Sinclair**

**Location: Dept. of Mech. Eng., Univ. of Toronto, 5 King's College Rd., Toronto, ON M5S 3G8, Canada**

**Abstract:**

While the scattering of a plane acoustic wave from a solid isotropic
cylinder has been extensively studied for the past several decades, very little
has been investigated regarding scattering from anisotropic cylinders. In this
paper, the mathematical formulation for the scattering of a plane acoustic wave
incident at an arbitrary angle (alpha) on an infinite transversely isotropic
cylinder is developed. The normal mode solution is based on decoupling of the SH
wave from the P and the SV waves. The resulting partial differential equations
have closed-form solutions and the scattered pressure field can be calculated at
any point outside the cylinder. The solution degenerates to the well-known
simple model for isotropic cylinders in the case of very weak anisotropy. The
validity of the mathematical model is verified first by applying it to the
familiar case of an isotropic aluminum cylinder. The model is then applied to a
transversely isotropic cylinder generated by perturbing various elastic
constants of the isotropic aluminum cylinder. The manner in which these
perturbations affect each of the Rayleigh, Whispering Gallery, and
longitudinally guided wave modes is shown to be consistent with elasticity
theory and modal shapes of these resonances. Some experimental results are also
presented.

from ASA 131st Meeting, Indianapolis, May 1996