Wave propagation in multilayer: effects of impulsive line source and rotating initial stress on Love-type wave in conductive polymer/PFRC composites

Purpose This study investigates Love-type wave propagation in a layered medium consisting of a functionally graded conductive polymer layer bonded to a functionally graded piezoelectric fiber-reinforced composite half-space, incorporating the effects of material gradation, piezoelectric coupling, viscosity, electrical conductivity and initial stress. Design/methodology/approach The governing electromechanical field equations, formulated in the presence of initial stress, are solved using the Fourier transform technique in conjunction with the Green’s function approach. A generalized dispersion relation for Love-type waves is derived by enforcing the continuity conditions at the layer – half-space interface and exploiting the symmetric properties of the Green’s function. Findings The obtained dispersion relation is subsequently reduced to the classical Love-wave dispersion equation under several particular cases, including the absence of initial stress, viscosity, conductivity, material heterogeneity and piezoelectric coupling. Numerical investigations illustrate the influence of initial stress along with other key physical and material parameters on the phase velocity characteristics of Love-type waves, and the recovery of the classical Love-wave equation as a limiting case confirms the correctness and robustness of the proposed formulation. Originality/value Numerical investigations illustrate the influence of initial stress along with other key physical and material parameters on the phase velocity characteristics of Love-type waves, and the recovery of the classical Love-wave equation as a limiting case confirms the correctness and robustness of the proposed formulation.