An Experimental Assessment of PZT Patches for Impedance-Based SHM Applications

In this paper, we present an alternative method for assessing the sensitivity of lead zirconate titanate (PZT) piezoceramics for damage detection in structural health monitoring (SHM) systems based on the electromechanical impedance (EMI) principle. An assessment of the sensitivity is obtained experimentally using the pencil lead break (PLB) method, which is frequently used in acoustic emission (AE) systems. Tests were carried out on an aluminum beam, and the results show a clear relationship between the damage indices obtained from the electrical impedance signatures of the PZT patch bonded to the monitored structure and the power spectral density (PSD) obtained using the PLB method.