Continuous Piezoelectric Health Monitoring Systems Based on Ultrasonic Guided Waves

摘要

Continuous strip transducers are investigated to generate ultrasonic guided waves for structural health monitoring of plate and shell structures. A theoretically driven approach, based on the application of wave mechanics principles, will be used to research and design a network of strip transducers. The initial transducer concept is that the strips will function like comb transducers and generate planar Lamb waves that travel normal to the longitudinal axis of the strip. Fibrous piezoelectric composites are considered for the comb elements, expanding the design space of these elements to include fiber orientation and volume fraction in addition to size, configuration, and location of the electrodes. This paper presents results from wave propagation studies of continuous strip actuators. As intended, the strip transducer excites Lamb waves that are reasonably planar with little interaction with the energy that propagates in the direction of the strip. Micromechanical modeling results for overall material properties of piezoelectric fiber composites are presented and demonstrate the wide design space for these types of devices.