Study on the methods of nondestructive testing and monitoring of rails is quite important nowadays in China, due to the fast development of railway system. Damage allocation also plays a crucial role in maintenance of railway systems. This paper proposed an active sensing system using piezoelectric (PZT) transducers to realize the real-time monitoring of the rails with accuracy and reliability. In this study, H-beams were used to mimic the rails in the experiment. PZT transducers were attached on the surface of rail flange as actuators and sensors to form the active sensing system. The study discussed different PZT transducer arrangements on the beams, and optimized the layout of transducers by comparing the signals with damage and without damage. The methods of time reversal and reflection waves were also explored for identification of the damage locations. Through our study, it shows that the proposed methods could access the health condition of the rails and could provide damage allocation with minor errors. The system has a potential to be applied for the structural health monitoring of long distance rails, and could provide early warnings based on the monitoring information.
doi: 10.12783/SHM2015/257