Non-destructive photoacoustic detecting method for high-speed rail surface defects

The rail defect detection is vital to the rapid development of high-speed rail. A new, easily available nondestructive testing method which applies the photoacoustic detection technology is proposed here for the rail defect detection. Based on the ultrasonic sensor, a real-time photoacoustic imaging system for the rail non-destructive testing is established. The model of the system and its numerical solution are built first, and then the corresponding experiments and analysis are conducted. The photoacoustic image with damage characteristics can be reconstructed through the photoacoustic signals which excited by pulsed laser and then reflected back from the rail surface. According to the reconstructed image, the damage information such as the appearance, extension trend, and the depth of the rail defect can be effectively identified. It has been proved that the established photoacoustic detecting method for high-speed rail surface detection is an effective and non-destructive detecting technology.