Nondestructive Evaluation Using Piezoelectric Wafer Active Sensors

The purpose of this research was to test methods of structural health monitoring using piezoelectric sensors. Piezoelectric wafer active sensors were used to detect water level and the presence of damage in a water tank. A pair of sensors was attached to the tank and a function generator was used to transmit an ultrasonic wave through the tank. This wave was analyzed to determine water level inside the tank and the presence of damage. Water level could be detected to within 0.5 cm and damage could be reliably detected, however, damage position could not be. An additional pair of sensors was added to allow water level and damage position to be changed simultaneously. With this additional set of sensors, changes in the wave reading due to water level could be differentiated from those due to damage