Scattering in the Time Domain from Submerged Elastic Shells at Coincidence Frequencies

Abstract

It is known that when scattering from elastic shells, a large resonance is produced at frequencies corresponding to values in which the flexural phase velocity is roughly equal to the speed of sound in the fluid. A systematic analysis indicates that the large response is due mainly to water born waves (labeled A waves) which have narrow half-widths and manifest themselves as pronounces spikes in the form function as well as weaker flexural resonances (labeled AO) which have rather larger half-widths and produce an envelop effect due to overlapping resonances over a broad frequency range. These results are analyzed within the context of a new time domain resonance scattering theory and are shown to produce characteristic transient return signals. From these signals it is possible to calculate both the half-width of the A waves as well as their group velocities.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1990
Accession Number
ADA231122

Entities

People

  • M. F. Werby

Organizations

  • United States Naval Research Laboratory

Tags

DTIC Thesaurus Topics

  • Acoustic Scattering
  • Carrier Frequencies
  • Elastic Shells
  • Fluids
  • Frequency
  • Frequency Bands
  • Group Velocity
  • Information Operations
  • Phase Velocity
  • Poisson Ratio
  • Rayleigh Waves
  • Resonance
  • Resonance Scattering
  • Scattering
  • Time Domain
  • Water
  • Waves

Fields of Study

  • Physics

Readers

  • Oceanography.
  • Spectroscopy.
  • Structural Dynamics.