Influence of Interfacial Stiffness and Density on Love-Type Wave Propagation in a Fiber-Reinforced and Fiber-Piezoelectric-Layered Medium

This study examines the propagation of Love-type waves in a layered smart composite structure consisting of a fiber-reinforced composite (FRC) layer over a piezoelectric fiber-reinforced composite (PFRC) half-space. A novel dual-membrane interface model is proposed, featuring a spring layer sandwiched between a regular (mechanical) membrane and an electromechanical (electric) membrane to capture both regular and electromechanical interfacial effects. Analytical dispersion relations are derived using an exact formulation, supplemented by a stress analysis of the electromechanical membrane to better understand interface behavior. A detailed parametric and comparative study is performed to assess the distinct and often contrasting roles of the two membranes in influencing Love-type wave characteristics. Results reveal that membrane stiffness, density, and spring constant significantly affect phase velocity trends. The model recovers classical Love-type wave results as limiting cases and provides a robust framework for tuning wave behavior in layered systems. These insights have direct implications for the design of advanced SAW devices, sensors, actuators, and non-destructive testing applications.