Gravity-Affected Reflected Waves Generated at the Surface of a Micro-Mechanically Modelled PFRC Half-Space

This study presents an analytical investigation of plane wave reflection phenomena in a gravity-influenced piezoelectric fiber-reinforced composite (PFRC) half-space, which was micro-mechanically modeled using Strength of Materials and Rule of Mixtures techniques. The model considers the oblique incidence of quasi-longitudinal (IqP) and quasi-shear vertical (IqSV) waves at a free surface separately, leading to the generation of reflected qP (RqP), qSV (RqSV) and electroacoustic (REA) waves. Plane wave solutions satisfying generalized Snell’s law are used to analytically obtain the propagation angles of these reflected waves, which are displayed graphically. Moreover, for qSV incidence, we established the existence of a critical angle ([Formula: see text]), beyond which, the RqP wave becomes evanescent. Using appropriate boundary conditions at the surface, the amplitude and energy ratios of all waves are obtained in closed form. These expressions are shown to satisfy the universal Energy Conservation Law, which in turn confirms the consistency of the model and validates the problem. The findings provide physical insights of direct relevance to gravity-sensitive wave propagation in smart composite structures, with potential applications in SHM, NDE, and geophysical exploration.