ASA 124th Meeting New Orleans 1992 October

3pSA4. Effects of circumferentially moving loads on the vibration and sound radiation of finite cylindrical shells.

Raymond Panneton

Alain Berry

Frederic Laville

GAUS, Mech. Eng., Univ. of Sherbrooke, Sherbrooke, PQ J1K 2R1, Canada

Sound radiation by circular cylindrical shells has been of interest for several years because this kind of structure is encountered in many products. Usually, the structures studied are circular cylindrical shells excited by stationary harmonic point loads. In the present case, a model is developed to calculate the vibrational response and sound radiation of a simply supported stiffened circular cylindrical shell excited by local or distributed circumferentially moving loads. This kind of system is a basic modelization of the ``pressure screens'' used in the pulp and paper industry. A variational approach is used to develop the analytical formulation to solve the problem. The results can be interpreted in terms of vibrational and acoustical parameters such as the quadratic velocity of the shell, the radiated sound power, and the radiation efficiency. Numerical results for various types of load and rotational speeds are presented and principal phenomena are discussed. Also, to validate the model, the theoretical results are compared to experimental results obtained for a simply supported cylindrical shell under circumferentially moving loads.