Ultrasonic guided waves for hidden damage detection in composite structures: Theory and experiments

Abstract

In this paper the theoretical knowledge base required for the development of a reliable structural health monitoring system based on ultrasonic guided waves is considered. An exact theory is used for relatively rapid calculation of the PZT driven surface motion in a plate recorded in an ultrasonic experiment. The theoretical results are compared with those obtained from an explicit fi nite element code for their mutual veri fi cation, showing excellent agreement. To determine the location and the severity of a damage with a minimal operator intervention, the ultrasonic wave propagation data are analyzed using a damage index approach carefully designed to overcome the complexity and variability of the signals in the presence of damage as well as the geometric complexity of the structure. © RILEM 2013.