## 3aSAa10. A general dynamic theory of thermopiezoceramic shells.

### Session: Wednesday Morning, May 15

### Time: 10:15

**Author: G. Askar Altay**

**Location: Dept. Civil Eng., Bogazici Univ., Bebek, 80815 Istanbul, Turkey**

**Author: M. Cengiz Dokmeci**

**Location: Istanbul Tech. Univ.--Teknik Univ., Taksim, 80191 Istanbul, Turkey**

**Abstract:**

This study presents a general theory for the motions of a ceramic shell in
which there is coupling among mechanical, electrical, and thermal fields. The
coated ceramic shell is treated as a two-dimensional thermopiezoelectric medium
and a separation of variables solution in terms of the thickness coordinates,
the midsurface coordinates, and time is sought for its field variables. Then, a
variational averaging procedure [M. C. Dokmeci, IEEE Trans. Ultrason.
Ferroelectr. Freq. Control 35, 775--787 (1988)] together with the solution is
used so as to derive the system of approximate equations of ceramic shell. The
invariant system of governing equations which are expressed in both differential
and variational forms accounts for all the types of motions of ceramic shells.
Certain cases involving special geometry, material properties, and motions are
considered [e.g., M. C. Dokmeci, J. Math. Phys. 19, 109--126 (1978)]. Also, the
sufficient boundary and initial conditions are given for the uniqueness in
solutions of the fully linearized system of shell equations. The results are
shown to generate a series of known shell theories [e.g., M. C. Dokmeci, IEEE
Trans. Ultrason. Ferroelectr. Freq. Control 37, 369--385 (1990) and references
therein]. [Work supported by TUBA-TUBITAK.]

from ASA 131st Meeting, Indianapolis, May 1996