Modeling and Experimental Study of Cross-Electromechanical Admittance for Crack Localization in Beams with Distributed Piezoelectric Wafers.

This research developed a novel crack localization technique that employed cross-electromechanical admittance (EMA), and its validity was verified through both analytical simulations and experimental measurements. Initially, an analytical model of the cross-EMA was established based on the transfer matrix method (TMM), and subsequently verified by experimental data and finite element analysis. Using the established model, the cross-EMA signatures were then utilized for crack localization in conjunction with a damage index defined as the correlation coefficient (CC). Furthermore, experimental investigations were carried out on five steel specimens, each of which was instrumented with multiple surface-bonded Lead Zirconate Titanate (PZT) wafers in a distributed manner. A crack with a width of 1.5 mm and a depth of 8 mm was introduced into each specimen to simulate structural damage. Both analytical investigations and experimental research have demonstrated that the cross-EMA signatures exhibit crack localization capabilities and can precisely reflect the local mechanical characteristics of the monitored structure.