ASA 125th Meeting Ottawa 1993 May

4pSA11. Experimental investigation of vibration excitation for structural sound radiation study.

Dany Couture

Yvan Champoux

Claude Lesage

G.A.U.S., Mech. Eng. Dept., Univ. de Sherbrooke, Sherbrooke, PQ J1K 2R1, Canada

Over the last decade, several models have been proposed for modeling the sound radiation of vibrating structures. These analytical or numerical models are frequently considered for simple or semi-complex structures such as plates and shells. They were sometimes validated through simple experiments and the theories were often judged valid when only trends between theory and experimental results were obtained. The discrepancies were almost systematically associated with the limitations of the experimental set up. In order to use experimental results as a basis to challenge or validate the theories, accurate results must be obtained. The precise measurement of the structure excitation is deemed necessary. Laterally flexible rods are often used between the shaker and the structure to avoid the introduction of unwanted excitations or the inadvertent modification of the structure. A load cell that measures moments and longitudinal force has been developed and was used to study the influence of different excitation configurations. Alignment must be taken into account. The use of flexible rods will be examined and useful guidelines will be established.