Propagation of SH waves in a visco-elastic layer overlying an inhomogeneous isotropic half-space

This paper is concerned with the propagation of SH-waves in an inhomogeneous viscoelastic layer overlying an inhomogeneous isotropic half-space. For the study of viscoelastic layer Kelvin–Voigt type model has been considered. The exponential type inhomogeneity is considered in viscoelastic layer with different parameters for viscoelastic part and for density of medium whereas for the half-space, it is quadratic type with single inhomogeneity parameter for rigidity and density. The solutions are obtained analytically for both the layer and half-space. Dispersion relation is obtained and subjected to continuity conditions at interfaces of viscoelastic layer and half-space and the upper boundary of layer as free surface. The effects of the inhomogeneity parameter are studied for both viscoelastic layer and inhomogeneous isotropic half-space. The numerical results are shown by plotting the graph between phase velocity and wave number for different values of inhomogeneity parameter and for the variation of depth of the layer. Keywords: SH-waves, Inhomogeneity parameter, Viscoelastic layer, Phase velocity, Wave numbe