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 2N 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.
 Publication:

NASA STI/Recon Technical Report N
 Pub Date:
 July 1979
 Bibcode:
 1979STIN...8021642H
 Keywords:

 Boundary Value Problems;
 Energy Absorption;
 Finite Element Method;
 Radiation Absorption;
 Rayleigh Waves;
 Viscoelasticity;
 Boundary Conditions;
 Computer Programs;
 Eigenvalues;
 Energy Transfer;
 Perturbation Theory;
 StressStrain Relationships;
 Communications and Radar