Actuation Model for Lamb Wave Excitation in Composite Plates Using Piezoelectric- Flexoelectric Actuators

Abstract

Among various SHM techniques, guide-wave-based methods are mostly explored for their effectiveness in damage detection. However, despite the growing interest in this area, no analytical models have been developed to date for the actuation of Lamb waves in composite structures using piezoelectric and flexoelectric transducers. This article develops a theoretical model for actuation of composite plates using physically modeled adhesively bonded piezoelectric-flexoelectric transducers. The model incorporates both interfacial shear and peel stresses at the interface of the actuator and host composite laminate. The tractions induced by the actuator onto the plate surface are determined by modeling the actuator and the laminated plate as Mindlin plates. The formulation results in a seventh-order differential equation for the interfacial shear stress, which is solved in closed form by satisfying stress-free boundary conditions at the actuator and plate edges. The peel stress is subsequently determined from the differential relation in terms of the interfacial shear stress. For validation, the longitudinal distributions of interfacial shear and peel stresses are compared with the ABAQUS’ continuum-based finite element results. A comprehensive numerical study has been performed to demonstrate the effect of adhesive and host laminate thickness on the distributions of interfacial shear stress and its peak amplitude.