Analysis of the accuracy in impact localization using piezoelectric sensors for Structural Health Monitoring with multichannel real-time electronics

The work presents a SHM electronic system with real-time acquisition and processing for the determination of impact location on an aerospace structure. The novelty of this work is the quantitative evaluation of impact location errors using the Lamb wave guided mode So, captured and processed in real time by up to eight piezoelectric sensors. The differential arrival times are used to minimize an error function for the position estimation. The results show quantitively the trade-off between the number of sensors used for the impact positioning and the error. The generated So mode signals propagated into a 1.4mm thick aluminum at the velocity of 5150m/s at the corresponding frequency of 650kHz, provide an error that is always less than on wavelength using eight sensors covering a 500mm x 500mm plate surface.