Energy Dissipation of Rayleigh Waves due to Absorption Along the Path by the Use of Finite Element Method

Abstract

A normally incident Rayleigh wave may be used for the investigation of a general vertical boundary and the attenuation of a viscoelastic medium. Use of energy conservation and proper boundary conditions produce 2 N second order differential equations, N being the number of viscoelastic layers in the medium. The homogeneous part of the differential equations can be transformed into an eigenvalue problem by the use of finite element technique; the eigenvalue and eigenvectors of the eigenvalue problem are the wavenumbers and the displacement amplitudes of the viscoelastic layered medium. The real and imaginary parts of the wavenumber determine the phase velocity and the attenuation of the layered medium, respectively. Dispersion and the attenuation curves can be obtained by using different periods. The above wavenumbers can be used in the inhomogeneous differential equation; this equation contains the effect of the vertical boundary; solution of this equation determines the displacement at the vertical boundary.

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Document Details

Document Type
Technical Report
Publication Date
Jul 31, 1979
Accession Number
ADA079645

Entities

People

  • Ali A. Feizpour
  • Eugene T. Herrin
  • Tom Goforth

Organizations

  • Southern Methodist University

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Acoustics
  • Air Force
  • Crystal Lattices
  • Crystal Structure
  • Differential Equations
  • Doppler Effect
  • Finite Element Analysis
  • Mechanics
  • Modulus Of Elasticity
  • New York
  • North America
  • Phase Velocity
  • Rayleigh Waves
  • Seismology
  • Surface Waves
  • United States
  • Wave Propagation

Fields of Study

  • Mathematics

Readers

  • Control Systems Engineering.
  • Electromagnetic Wave Scattering and Antenna Radiation Engineering