Rail Inspection Using Noncontact Laser Ultrasonics

Abstract

In this study, a noncontact laser ultrasonic system is proposed for rail defect detection. An Nd-Yag pulse laser is used for generation of ultrasonic waves, and the corresponding ultrasonic responses are measured by a laser Doppler vibrometer. For the detection of rail surface damages, the shape of the excitation laser beam is transformed into a line. On the other hand, a point source laser beam is used for the inspection of defects inside a rail head. Then, the interactions of propagating ultrasonic waves with defects are examined using actual rail specimens. Amplitude attenuation was mainly observed for a surface crack, and reflections were most noticeable from an internal damage. Finally, opportunities and challenges associated with real-time rail inspection from a high-speed train are discussed.

A Fully Optical Laser Based System for Damage Detection and Localization in Rail Tracks Using Ultrasonic Rayleigh Waves: A Numerical and Experimental Study

“…However, the rail tracks may be subjected to constant and fluctuating loads over different times of service which may result in development of micro and macro scale damages in the rail material especially over the surface. This may consequently decrease the load bearing capacity of the rail track and eventually may result in failure and de-railing resulting into loss of economy and human life [1][2].…”