Wheel wear performance assessment and model validation using Harold full scale test rig

The railway industry has focused on the improvement of maintenance through the use of novel technologies. Recently, the utilisation of repair welding to restore the worn area on wheels has been investigated, as it can bring significant savings in wheelset maintenance. Under an Innovate UK AURORA project, a worn wheel that previously operated on London Underground (LUL) was restored using this process. To test its performance and compare with a new standard steel grade wheel, the HAROLD full scale test rig was used in which an LUL vehicle bogie equipped with both the restored and R9 grade wheels was operated under the representative lateral and yaw displacements computed from vehicle dynamics simulations. The wear measurements carried out at the end of test cycles showed that although the restored wheel suffered from initial higher wear, the levels reduced and became similar to the R9 grade wheel. Furthermore, the full-scale testing provided an opportunity to validate the wear model predictions which were conducted using the vehicle dynamics simulations utilised in testing inputs. It was found that while the flange wear predictions were higher, the tread wear estimations were smaller than the measurements on the R9 grade wheel.