A numerical procedure for the wheel profile optimisation on railway vehicles

The reduction of wear due to wheel-rail interaction is a fundamental aspect in the railway field, mainly correlated to safety, maintenance interventions and costs. In this work, the authors present an innovative wheel profile optimisation procedure, specifically designed with the aim of improving the wear and stability behaviour of the standard ORE S1002 wheel profile matched with the UIC60 rail profile canted at 1/20rad, which represents the wheel-rail combination adopted in Italian railway line; this matching shows poor wear performance due to the non-conformal contact. A new wheel profile, conventionally named DR2, has been developed by the authors in collaboration with Trenitalia S.p.A. The DR2 wheel profile is designed to guarantee the same kinematic characteristics of the matching formed by ORE S1002 wheel profile and UIC60 rail profile with inclination angle p equal to 1/40 rad, widely common in European railways and characterised by good performances in both wear and kinematic behaviour. The evolution of wheel profiles due to wear has been evaluated through a wear model developed and validated by the authors in previous works. In the present research the investigated trainset is the passenger vehicle ALSTOM ALn 501 Minuetto, which is usually equipped with wheelsets having the standard ORE S1002 wheel profile in Italian railways. The entire model has been simulated on a virtual track specifically developed to represent a statistical description of the whole Italian line; the innovative statistical approach has been employed to obtain accurate results in reasonable computational times. The data necessary to build the virtual track and the vehicle model were provided by Trenitalia S.p.A. and Rete Ferroviaria Italiana (RFI).