Interfacial Wave Propagation at Spring Contact of Functionally Graded Fiber-Reinforced and Isotropic Elastic Semi-Infinite Media

Abstract

An analytical approach has been presented in this research article to investigate the propagation properties of Stoneley waves at an imperfect interface between two elastic semi-infinite media with distinct properties. A model comprising an isotropic elastic semi-infinite medium is considered overlaid by a functionally graded fiber-reinforced elastic semi-infinite medium with spring contact. The analytical method is utilized to derive expressions of stress and displacement components for the considered materials. The frequency relation of Stoneley wave propagation is obtained by employing appropriate boundary conditions. In particular cases, the frequency relations are also discussed for different types of boundaries, such as normal stiffness, transverse stiffness, sliding contact, complete debonding, and welded contact. The obtained results are assessed analytically by comparing it with the well-established classical case examined in the existing literature. A comparative analysis between the proposed model and the classical case of Stoneley wave propagation is also discussed in detail. The graphical representations of dispersive and damping curves with various attributes are demonstrated to enhance our understanding of the Stoneley wave propagation behavior. This research article explores the propagation characteristics of Stoneley waves in a functionally graded fiber-reinforced elastic semi-infinite medium overlying an isotropic elastic semi-infinite medium with spring contact. Fiber-reinforced composites are widely recognized and valued engineering materials because of their versatility in diverse applications. The involvement of functionally graded and imperfect boundaries in the anisotropic structure holds substantial importance from both geological and engineering perspectives; it also facilitates the simulation of more realistic elastodynamics models. This analysis identifies the physical factors that cause the degradation and elevation of Stoneley wave propagation. The findings are valuable in subsurface imaging and seismic exploration, where the propagation of Stoneley waves plays a crucial role in characterizing geological interfaces, mapping subsurface structures, and detecting faults. Additionally, the research has significant potential to advance the assessment of material integrity in construction, such as concrete and other engineered materials.