1 PIEZOELECTRIC WAFER ACTIVE SENSORS (PWAS) FOR STRUCTURAL HEALTH MONITORING AND EMBEDDED ULTRASONICS

The capabilities of embedded piezoelectric wafer active sensors (PWAS) to perform in-situ ultrasonics for active structural health monitoring (SHM) and nondestructive evaluation (NDE) are explored. The paper shows that PWAS, though low-power, light-weight, and small, can successfully perform Lamb wave transmission and reception, pitch-catch and pulse-echo, as well as large area scanning using the phased-array principle. The opportunities for implementation in structural health monitoring systems and the needs for further research are also discussed