Assessment of reliability performance of fatigue crack detection by intelligent coating monitoring and pzt sensors

Structural Health Monitoring (SHM) utilizes sensor network system embedded within structure to evaluate the size and location of structural damage, and perform the remaining useful life prediction and reliability assessment. Lead Zirconate Titanate Piezoelectric (PZT) and Intelligent Coating Monitoring (ICM) sensors are two types of sensors which have been reported for efficient damage detection in real engineering fields. For ICM sensors, the resistance variation of the sensing lay is used to characterize the fatigue crack propagation. For PZT sensors, changes which are caused by discontinuities in the wave propagation path are used to characterize damage. However, most of current researches focus on damage diagnosis using specific sensor technique such as PZT and ICM sensors. A comparative study of the reliability performance of PZT and ICM sensors is proposed in this paper. Fatigue crack growth experiments using both PZT and ICM sensors are designed to study the reliability performance of these two sensor techniques. The reliability of fatigue crack detection for PZT and ICM sensors are evaluated by two aspects: the accuracy of crack quantification and the reliability of crack detection, which is quantified by Probability of Detection (POD) method.