Nonlinear and Random Phenomena in Electromagnetic and Acoustic Wave Propagation.

Abstract

The acoustoelastic effect is the dependence of sound speed upon stress in an elastic solid due to nonlinearity. This effect can be used for nondestructive testing of structural components of aircraft, vehicles, etc. A theory of the effect was developed which involved analyzing acoustic wave propagation in random anisotropic solids. A related theory of the effective elastic constants of solids composed of aggregates of polycrystals was also developed. For anisotropic composite materials reciprocal relations satisfied by their effective thermal or electrical conductivity tensors were discovered. In the case of scalar materials such relations have been very useful, so the new ones may be useful too. It has also been shown how the elastic properties of the ground could be determined from seismic scattering data. This method used the Born approximation, and led to results involving Fourier transforms. Keywords: Electromagnetic wave propagation; Acoustic wave propagation; Acoustoelastic effect; Random media; Nonlinearity.

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Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1987
Accession Number
ADA181649

Entities

People

  • Joseph B. Keller

Organizations

  • Stanford University

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Acoustic Waves
  • Born Approximations
  • Composite Materials
  • Conductivity
  • Elastic Properties
  • Electrical Conductivity
  • Electromagnetic Wave Propagation
  • Inverse Scattering
  • Materials
  • Military Research
  • Nondestructive Testing
  • Polycrystals
  • Scattering
  • Structural Components
  • Wave Propagation
  • Waves

Readers

  • Materials Science and Engineering.
  • Plasma Physics / Magnetohydrodynamics
  • Structural Dynamics.