The detection of damages by modal analysis and similarvibration techniques depends upon the knowledge and estimation ofvarious modal parameters. In addition to the associated difficulties,such low-frequency dynamic response based techniques fail to detectincipient damages. Smart piezoelectric ceramic(PZT) transducers,which act both as actuators and sensors in a self-analyzing manner,are emerging to be effective in non-parametric health monitoring ofstructural systems. In this paper we present the results of anexperimental study for the detection and characterization of damagesusing PZT transducers on aluminum specimens. The method of extractingthe impedance characteristics of the PZT transducer, which iselectromechanically coupled to the host structure, is adopted fordamage detection. Three types of damage are simulated and assessed bythe bonded PZT transducers for characterization. We present theeffectiveness of PZT transducers in the detection andcharacterization of incipient damages without the need to know themodal parameters. The PZT transducers are found to have asignificantly large sensing area for detecting even small incipientdamages. The possibility of replicating the pristine state signaturesof different transducers under similar conditions of bonding andgeometrical location is also explored. For appropriatecharacterization of damages, a few statistical signature patternrecognition techniques are evaluated.
展开▼
Division of Structures and Mechanics, School of Civiland Structural Engineering, Nanyang Technological University,Block N1, 50 Nanyang Avenue, 639798, Singapore;
