3. Characterization of Shear Horizontal-Piezoelectric Wafer Active Sensor (SH-PWAS)

This paper discusses shear horizontal SH-coupled piezoelectric wafer active sensor (PWAS). The paper starts with a review of the state of the art in modeling SH transducers and their importance in non-destructive evaluation (NDE) and structural health monitoring (SHM). This is followed by basic sensing and actuation equations of shear-poled PWAS transducers. The free SH-PWAS electromechanical (E/M) impedance analytical models are presented, and compared with finite element models (FEM) and experiments. In this study, we extend the analytical development for constrained SH-PWAS bonded to structure on the form of beams. The model is based on normal mode expansion (NME) technique. The interaction between the SH-PWAS and the structure is studied. We developed closed-form equation of structure dynamic stiffness by coupling the mechanical response solution of the SH-PWAS to the structure elasticity solution. Finite element simulations and experiments matched well with analytical predictive model. Impedance spectroscopy is also used in NDE and SHM for composites. We present a predictive FEM for the E/M impedance of bonded SH-PWAS on cross ply GFRP as well as [0/45/45/0]s CFRP plates. The paper ends with summary, conclusion, and suggestions of future work.