ASA 125th Meeting Ottawa 1993 May

5aSA3. Scattering from submerged elastic shells and the characterization of resonances at coincidence frequency: A consensus view.

Michael F. Werby

Code 7181, NRL, Stennis Space Center, MS 39529-5004

Roger H. Hackman

Palo Alto Res. Lab., Palo Alto, CA 94304-1191

H. Uberall

Catholic Univ. of Am., Washington, DC 20064

Gary Steven Sammelmann

CSS, Code 130B, Panama City Beach, FL 32407

In the neighborhood of coincidence frequency for submerged shells (the frequency at which the flexural phase velocity for a plate or shell equals the phase velocity of the speed of sound in the ambient fluid), very large returns are observed which typically include large amplitude narrow spiked returns superimposed on a broad Gaussian shaped return. Each of us as well as the French group (M. Talmant and G. Quentin, University of Paris, 7) have ventured an interpretation of these events for which the interpretations are fairly consistent with some minor variations in detail. As in any new study, differing language was employed. This presentation offers a consensus view of the event along with proposed language for future use.