ASA 124th Meeting New Orleans 1992 October

4pSA2. Acoustic radiation from a multilayer sandwich plate subjected to a point-harmonic excitation.

M. Kim

Y. F. Hwang

Carderock Div., Naval Surface Warfare Ctr., Bethesda, MD 20084-5000

An exact mathematical formalism was developed to calculate the acoustic response of a fluid-loaded, multilayer, sandwich plate subjected to a point-harmonic excitation. The plate can be fluid loaded on each side with arbitrary acoustic media. The solution was verified with asymptotic solution of a fluid-loaded thin steel plate. Numerical examples are presented for the acoustic radiation into water from various plate configurations subjected to a point force acting on its dry (air) side. The plate configurations considered are: (1) a two-layer elastic/viscoelastic plate, (2) a three-layer symmetric elastic/viscoelastic/elastic sandwich plate, and (3) a three-layer nonsymmetric elastic/viscoelastic/elastic sandwich plate with the viscoelastic layer given a range of different material properties (elastic constants, damping) and thicknesses. To elucidate the radiation mechanisms, the behavior of the modes of wave propagation in the plate is discussed. [Work supported by ONR.]