Research on Rail Flaw Echo Accurate Location Method Based on Interface Wave Tracking Technology

Abstract

In the calculation of rail flaw echo location, the rail flaw location is related to the ultrasonic propagation time in rail. The more accurate the extracted propagation time, the more accurate the rail flaw location calculation. During high speed rail flaw detection, unevenness in the vertical direction of the rail, structural differences in the detection wheel lifting unit and differences in the amount of fluid filled in the detection wheel will cause vertical jump of the detection wheel, leading to changes in ultrasonic arriving time at the rail surface of different probes and influencing flaw localization. Therefore, the paper proposes a rail flaw echo accurate localization method based on interface wave tracking technology. Taking 45° and 70°probes as examples, flaw echo localization based on interface wave tracking technology and the effectiveness of interface wave tracking technology under different pressure conditions of detection wheels are analyzed. An artificial flaw test block is designed, and flaw detection experiment is carried out and verified. The results show that interface wave tracking technology can guarantee precise extraction of ultrasonic echo time of different probes in the detection wheel(the time accuracy is 0.025 μs), and it is beneficial for rail flaw localization. In addition, based on the analysis of actual detection data of rail lines, suggestions for the application of interface wave tracking technology in flaw detection are proposed.

Keywords

• rail flaw detection vehicle
• ultrasonic detection
• interface wave tracking
• flaw location