Selective Observation of Elastic-Body Resonances via Their Ringing in Transient Acoustic Scattering.
Abstract
An elastic body immersed in a fluid will ring when isonified by sound whose frequency is the same as one of the resonances of that body. Correspondence has been established between these normal mode resonances of the body and the individual circumferential waves predicted by creeping wave theory. Isonifying the target by a relatively long sinusoidal wave train, with a narrow spectrum centered around, or away from, a selected resonance frequency, results in a series of superimposed responses consisting of the specular reflection and succession of creeping waves arriving after repeated circumnavigations of the body which, at resonance only, add in phase to generate the ringing response. Echoes from spherical targets are analyzed in this fashion, and are also associated with the resonance poles in the complex frequency plane, obtained by us in the form of contour plots. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 12, 1984
- Accession Number
- ADA145868
Entities
People
- H. Ueberall
- S. K. Numrich
- W. E. Howell
Organizations
- The Catholic University of America