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

## 4pEA11. The combined finite element and hybrid-type infinite element
analysis for complex structure underwater transducers.

**Jong-Rak Yoon
**

**
Chun-Duck Kim
**

**
**
*Dept. of Telematics Eng. and Dept. of Elec. Eng., Natl. Fisheries Univ. of
Pusan, Pusan, Korea 608-737
*

*
*
A numerical method for evaluating the electroacoustical characteristics of
a complex structure of transducer immersed in an infinite acoustic medium is
adopted. The mechanical, electrical, and acoustical response of the transducer
in the finite region is modeled by the finite element method; the Sommerfeld
radiation condition to the infinite region is modeled by the hybrid-type
infinite element method, and the boundary between both regions is formulated
with compatibility of the acoustical admittance in both regions. The numerical
results, which include the elastic response, the radiation impedance, and the
input electrical admittance, are given for a single piezoelectric cylinder and
a coaxial two piezoelectric cylinder array with various polyurethane windows.
The technique allows one to interpret and to optimize design parameters such as
geometrical shape and mechanical properties of structure components, electrical
characteristics of piezoelectric elements, etc.