### ASA 130th Meeting - St. Louis, MO - 1995 Nov 27 .. Dec 01

## 2pSA9. Hybrid asymptotic-numerical method for evaluating diffraction
coefficients.

**Paul E. Barbone
**

**
Isaac Harari
**

**
**
*Dept. of Aerospace & Mech. Eng., Boston Univ., Boston, MA 02215
*

*
, and Dept. of Solid Mechanics, Mater. and Structures, Tel-Aviv Univ.,
69978 Ramat Aviv, Israel
*

*
*
In complicated structural acoustics problems, the lack of relevant
diffraction coefficients often limits the applicability of the geometrical
theory of diffraction. A hybrid asymptotic/finite-element method is described
that lends itself to the numerical evaluation of diffraction coefficients. It is
based on the method of asymptotic patching. The farfield asymptotic expansion of
the scattered field is patched to a finite-element interpolation of the field
near the point of diffraction. This idea leads to the definition of an
asymptotically equivalent boundary-value problem, which is defined on a small
domain and therefore is efficiently discretized. The method is demonstrated with
an application to diffraction by an imperfect wedge. [Work supported by ONR.]