Novel SH-wave propagation modeling in fluid-loaded piezoelectric viscoelastic fiber-reinforced composites

This study develops a theoretical model for a piezoelectric viscoelastic fiber-reinforced composite (PVFRC) using the Rule of Mixtures and Strength of Materials. The model is applied to investigate shear horizontal (SH) wave propagation in a layered system consisting of a conductive fluid over a PVFRC substrate, capturing coupled fluid–piezoelectric–mechanical interactions. A non-ideal interface is introduced using Aifantis-type strain-gradient dual electromechanical membranes with a sandwiched electrically induced spring layer to represent imperfect bonding. Stress analysis of the membranes is performed to derive the governing electromechanical equations and describe stress–strain distributions. An exact dispersion relation is obtained under plane deformation conditions. A detailed parametric study examines the effects of piezoelectric coupling, strain-gradient parameters, interfacial stiffness, and fiber volume fraction on phase velocity. A comparative analysis of mechanical, classical, and coupled spring-type interfaces highlights their distinct influence on wave transmission. In addition, a physics-consistent artificial neural network (ANN) model is developed to accurately predict SH-wave phase velocity from the analytical data. The results provide a practical framework for controlling wave propagation in smart composite systems for vibration and energy applications.