Numerical study for a new methodology of flaws detection in train axles

• Published in: Ultrasonics Vol. 54; no. 3; pp. 841 - 849
• Main Authors: Mineo, C., Cerniglia, D., Pantano, A.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.03.2014
• Subjects: Axles; Computer Simulation; Equipment Design; Equipment Failure Analysis - instrumentation; Inspection; Laser ultrasound; Manufactured Materials - analysis; Materials Testing - instrumentation; Models, Theoretical; Nondestructive testing; Numerical method; Railroad wheels; Railroads; Railroads - instrumentation; Railway axle; Railway engineering; Railways; Trains; Ultrasonography - instrumentation; Numerical method; Railway axle; Laser ultrasound
• ISSN: 0041-624X; 1874-9968
• DOI: 10.1016/j.ultras.2013.10.008

•Current NDT techniques for railway axles require their disassembly from the bogie.•We investigate a new methodology for the detection of surface defects in train axles.•Non-contact ultrasound paves the way for in-service inspection at trackside stations.•The numerical results encourage experimental testing of the new approach. Train loads and travel speeds have increased over time, requiring more efficient non-destructive inspection methods. Railway axles are critical elements; despite being designed to last more than 20years several cases of premature failure have been recorded. Train axles are inspected regularly, but the limits associated to the traditional inspection technologies create a growing interest towards new solutions. Here a novel non-destructive inspection method of in-service axles based on non-contact data collection is presented. The propagation of surface waves, generated by a thermo-elastic laser source, is investigated using a finite element method based on dynamic explicit integration. Coupled thermo-mechanical simulations allow visualization of the ultrasonic field guiding the definition of the optimal NDT setup. The geometry of the axle and of the elements mounted on it is accurately reproduced; moreover the press fit effect caused by the wheel and the bearing rings is implemented. The current NDT techniques for railway axles require removing wheels and other components from the axle. The presented scheme uses non-contact ultrasonic generation and detection allowing non-contact in-service inspection of railway axles at trackside station. The numerical results are promising and encourage us to test the new approach experimentally.