ASA 124th Meeting New Orleans 1992 October

1pPAa7. Resonances of a finite elastic cylinder with hemispherical endcaps.

D. Decultot

F. Lecroq

G. Maze

J. Ripoche

LAUE, Univ. of Le Havre, Place Robert Schuman, 76610 Le Havre, France

M. F. Werby

Code 221, Naval Res. Lab., Stennis Space Center, MS 39529-5004

Jan Niemiec

David Taylor Res. Ctr., Carderock, MD 20084-5000

X. L. Bao

H. Uberall

Catholic Univ. of America, Washington, DC 20064

Experiments on ultrasonic backscattering from submerged elastic cylinders with hemispherical endcaps have been carried out for solid steel cylinders at Catholic University, for solid tungsten carbide cylinders at the University of Le Havre, and for hollow air-filled steel cylindrical shells at DTRC and Le Havre. The experimental results will be presented, and will be theoretically interpreted by the method of phase matching, taking into account the dispersion of the wave speed of the surface waves propagating axially along the cylinder (guided waves). Use of these explicit dispersion formulas, rather than their high-frequency constant limits as they have been employed previously (thereby neglecting transverse curvature effects) is shown to be very important in the correct identification of the resonance peaks.