Development of a phased array inspection system for the testing of railway solid axles from the end face

The structural integrity of wheelsets used in rolling stock is of great importance to the rail industry and its customers. In the last 15 years, 33 deaths and 48 injuries have occurred in Europe alone due to train axle failures. Visual inspection, magnetic particle inspection (MPI) and conventional ultrasonic testing are the current standard inspection practices used for manual non-destructive testing (NDT) of axles. However, some of these inspection processes require removal of the wheelset from the wagon/locomotive bogie and the full disassembly of the wheelset in order to facilitate access. Phased array (PA) ultrasonic techniques can provide the required flexibility and inspection capabilities to carry out testing of train axles from the end face without requiring disassembly of axle and bogie. This paper presents the development work carried out in AxleInspect collaborative project to develop a PA inspection system for the in-situ testing of solid axles having different diameters from the end face with minimum dis-assembly. This paper describes the design of the solid axle scanner and its integration with the PA inspection system (software, pulser-receiver and PAUT probe). Finally, experimental results obtained from the overall system from a variety of railway solid axles are presented.