Overview and Future Development of Rails Nondestructive Inspection

Rails are the foundation of railway transportation. The defects of rails directly and seriously affect the safety of railroad vehicles. The history and present situation of rails non-destructive inspection were introduced. For the issues of the traditional ultrasonic inspection method, the recent developments of rails non-destructive new techniques were reviewed, including the laser ultrasonic technique, the phased array ultrasonic technique, the electromagnetic acoustic technique, the ultrasonic guided waves technique, the acoustic emission technique, the electromagnetic measurement technique, the optical image and visual inspection technique, the fiber optical sensors measurement technique and vehicle-track interaction monitoring technique. With the analysis and comparison of the different non-destructive methods, the future developments of rails non-destructive inspection technique were discussed.