Impact of Electro-Mechanical Interfacial Imperfection on Rayleigh Wave Propagation in Piezo-Self-Reinforced Layered Structure Under Gravity

PurposeThis study presents an analytical approach to investigate the behaviour of Rayleigh waves in a functionally graded piezoelectric layer positioned between another functionally graded piezoelectric layer and a self-reinforced half-space under the influence of gravity.MethodsClosed-form analytical expressions for the displacement field and electric potential of Rayleigh waves are derived using a time-harmonic solution approach, with appropriate boundary conditions at electrically and mechanically bonded interfaces. Suitable transformations are employed to obtain the analytical form of frequency equations for Rayleigh waves under electrically short and electrically open conditions.ResultsNumerical simulations for a specific geophysical model have been conducted, with results presented through multiple plots to analyse the impact of material gradation, electromechanical imperfections, piezoelectricity, and gravity on the resultant velocity profile of Rayleigh waves. The influence of the dielectric coefficient on the phase velocity of Rayleigh waves is also examined and illustrated against the dimensionless wave number. Validation of subcases is also discussed.ConclusionsThe study reveals that the velocity of Rayleigh waves consistently decreases as the wave number increases, irrespective of electrical conditions. The gradient parameter exhibits a trend of increasing impact under electrically short conditions but shows nuanced variations under electrically open conditions across different wave number ranges. Additionally, the findings highlight the significant effects of other influential parameters on Rayleigh wave velocity. This research provides a theoretical foundation for the development and analysis of Surface Acoustic Wave (SAW) devices, Non-Destructive Testing (NDT), smart structures including actuators and resonators, and energy harvesting systems, offering enhanced performance and versatility.