Wave propagation modeling of the PZT sensing region for structural health monitoring

Despite various successful applications of lead zirconate titanate (PZT) material for structural health monitoring (SHM), the fundamental research work of determining the PZT sensing region is still needed. Among a variety of issues in relation to the PZT sensing region, this paper focuses on one of the most important factors, the material and structural damping. The elasticity solution of PZT generated wave propagation is first derived in terms of the wave reflection and transmission matrices. Subsequently, based on the corresponding principle, the viscoelasticity solution is obtained directly from the elasticity solution. Finally, the output voltage of the PZT sensor is calculated according to the PZT-structure interaction effect. In the experiment, an aluminum beam specimen bonded with PZT actuators as well as PZT sensors is tested. The output voltages of sensors are compared with the theoretical predictions to verify the developed model and to determine the reliable sensing region of PZT transducers.