Modeling of Guided-wave Excitation by Finite-dimensional Piezoelectric Transducers in Composite Plates

This paper addresses modeling of guided-wave excitation by surface-bonded piezoelectric wafer transducers in multi-layered composite plate structures. Each of the individual layers is assumed to have unidirectional fibers in an epoxy matrix and is modeled as being transversely isotropic. The piezoelectric actuators are modeled as causing shear traction along their edges on the plate surface and uncoupled actuator-substrate dynamics are assumed. The formulation is generic enough to accommodate arbitrary shape actuators, and specific expressions are derived for the cases of rectangular and ring-shapes. The surface and interfacial conditions are implemented using the global matrix approach. Since the three-dimensional guided-wave field is modeled without using reduced structural formulations, all possible guided-wave modes are captured. The two-dimensional spatial Fourier transform is used to solve the problem, and a rigorous inversion procedure is outlined. These models are implemented numerically and results in the form of harmonic radiation plots are presented for various configurations.