### ASA 125th Meeting Ottawa 1993 May

## 3aSA10. Vibrations and acoustic radiation of a simply supported
cylindrical shell under circumferentially moving loads: Modeling and
experiments.

**Raymond Panneton
**

**
Frederic Laville
**

**
Alain Berry
**

**
**
*G.A.U.S., Univ. of Sherbrooke, Sherbrooke, PQ J1K 2R1, Canada
*

*
*
The vibrational and acoustical behaviors of a simply supported cylindrical
shell, immersed in a light fluid and excited with circumferentially moving
radial loads are considered in the frequency domain. The equation of motion is
developed using an energy method. To solve the problem, the shell displacements
and boundary pressures are expanded in a series of in vacuo shell modes. The
circumferentially moving loads induce a displacement with spatial and temporal
dependences of the form e[sup jN(cursive phi)] and e[sup -jN(Omega)t], where N
is an integer and (Omega) is the rotational speed of the loads. For this type
of dependence, the equation of motion shows critical speeds for which the modal
amplitudes are maximum. Also, a modal analysis is conducted to describe the
general behavior of the shell, in the frequency domain, in terms of quadratic
velocity, radiated sound power, and radiation efficiency under moving loads.
This analysis shows that high levels of quadratic velocity and radiated sound
power occur for the critical speeds of rotation. In order to validate this
modeling, numerical results are compared with previous published works and
laboratory experiments. This paper is the continuation of the paper presented
at 124th ASA Meeting [J. Acoust. Soc. Am. 92, 2387 (A) (1992)].