Failure of rail axle bearings: saving train passengers time and money

Underpinning our research is failure investigations and Tribology – the science and engineering of interacting surfaces in relative motion, including the study and application of the principles of friction, lubrication and wear.  Our scientists relied on their expertise in this area to address the project’s challenges.

Through extensive fractography, our researchers confirmed that the bearing surfaces were damaged via a mechanism called Rolling Contact Fatigue (RCF).

These fractographic examinations included surface profilometry, optical microscopy, scanning electron microscopy and computer tomography.  We also examined historical vibration data in conjunction with the measurable parameters of the physical damage observed.

Initial indications of a relationship were found when we examined many example bearings removed from service. However, the next stage of the work will allow us to create our own damaged bearings with our new full-scale rail-axle bearing test rig, provided by Perpetuum and housed at the University.

Funding

This research has been funded by Perpetuum Ltd, the IAA-KTS funding from the Engineering and Physical Sciences Research Council and by WARNTRAK 672265 (Horizon 2020-SMEINST-2-2014).

We were awarded £1.1M by Innovate UK’s Accelerating Innovation in Rail competition to design and build a four-point rotating bend rig to simulate a rail axle in service. This award was achieved in collaboration with Perpetuum and TWI.

By using condition monitoring, over 30% (£3 billion p.a.) could be saved worldwide just for passenger train bogie maintenance, with the added benefit of major improvements in safety and reliability.

Perpetuum's Energy Harvester powered wireless sensor systems have been successfully installed for on-board and real-time condition monitoring of bearings and wheels. This project itself will develop the capability of the damage detection system to become diagnostic, and eventually prognostic. Our work will also impact other sectors as rolling element bearings are widely used in helicopters, wind turbines, engines and power plants, etc.

A recent development of this work has led to the design, build and assembly of a full-scale rail-axle bearing test rig, to mimic the loads and speeds of a commuter train on the subject bearing. This brand new and unique academic facility will provide our scientists with the information to further investigate the degradation of large rolling element bearings.

We used the following facilities within the University - Multidisciplinary, Multiscale, Microtomographic Volume Imaging Centre; Full Scale Bearing Test Rig.

Find out more about the Engineering and Environment Faculty's many world class facilities.

We are grateful to Southeastern Railways for their access and support during this project.

Our research partners in this project are Perpetuum and Southeastern Railways.

This research project forms part of the University's nC2 Enterprise Consultancy Unit.

N. Symonds, I. Corni, R.J.K. Wood, A. Wasenczuk, D. Vincent, Observing early stage rail axle bearing damage, Engineering Failure Analysis 56 (2015) 216–232

I. Corni, N. Symonds, C. E. Birrell, O. L. Katsamenis, A. Wasenczuk, D. Vincent, Characterization and mapping of rolling contact fatigue in rail-axle bearings. Engineering Failure Analysis 82 (2017) 617–630.

I. Corni, N Symonds, A Wasenczuk and D Vincent, On-board condition monitoring of rail axle bearings using vibration data, The International Journal of Condition Monitoring, 8 (2018), in press.