Analytical approach to determine the impact of line source on SH-wave propagation in an anisotropic poro-viscoelastic layered structure in the context of Eringen's nonlocal elasticity theory

Abstract The present contribution investigates the influence of line source on the propagation of Horizontally polarized shear waves (SH-waves) in a complex stratified structure which comprises two distinct nonlocal anisotropic fluid-saturated poro-viscoelastic layers resting over a nonlocal functionally graded anisotropic fluid-saturated poro-viscoelastic substrate. Based on Eringen's nonlocal elasticity theory, constitutive relations and equations of motion for a nonlocal anisotropic poro-viscoelastic medium are developed in this article. Green's function technique and Fourier transformation are applied in this study to acquire the complex frequency relation of the propagating waves in the context of suitable boundary conditions. Dissociation of the complex frequency equation into real and imaginary parts leads to two distinct equations featuring dispersion and attenuation properties of SH-waves in the considered model, respectively, which represent significant relevance to the field of geophysics, earthquake engineering and civil engineering. As a special case of the problem, the closed form of the dispersion equation has been derived for a structure with a single porous layer overlying a semi-infinite medium which has been validated with the pre-established result and the final particular case is in well agreement with the classical Love wave equation. Several graphs are plotted to demonstrate the impact of functionally graded parameter, ratio of widths of two layers, quality factors, and dissipation parameter on the dispersion and attenuation of SH-waves. Moreover, the graphical implementation of the variation in shear wave speeds of each medium due to the change in nonlocal parameter is one of the major highlights of this study.