Analysis and Flaw Recognition Application of 70o Probe Echoes for Rail Flaw Detection Vehicles

Abstract

This paper delves into the impact of abnormal echoes at the rail head on flaw recognition resulting from the central 70° probes on rail flaw detection (RFD) vehicles. Using B-scan data showcasing such 70° probe echoes near a transverse crack at the rail base on a rail flaw detection calibration track, this study elucidated the ultrasonic propagation path through analysis, theoretical calculations, and software simulation. The results identified these echoes as ghost echoes, originating from ultrasonic emissions by the central 70° probe and subsequently reflecting from the transverse crack at the rail base. Meanwhile, considering the characteristics of such ghost echoes, this paper presents practical suggestions for flaw recognition applications under the scenario of 70° echoes near a transverse crack at the rail base and a weld seam. The characteristics of such 70° probe echoes summarized in this paper can improve flaw recognition accuracy and reduce false alarming rates in rail detection.

Keywords

• rail flaw detection vehicle
• ultrasonic
• ghost echo
• transverse crack at rail base