Non-Hertzian wheel-rail contact modelling for real-time simulation: a case study in hardware-in-the-loop test

Numerical simulation of rail vehicle dynamics has been developed over more than half a century, progressively enhancing the scope and accuracy of the numerical models with the increasing availability of computational resources. The rapid advancement of Hardware-in-the-Loop (HiL) testing and digital twin is recently fostering further development of numerical methods for the design of rail vehicle technologies. However, these promising technologies impose stringent demands on the computational efficiency of the numerical models to facilitate real-time simulations, imposing the search of a trade-off between accuracy and computational efficiency. A critical aspect for enhancing both model accuracy and efficiency is the modelling of wheel-rail contact. In this paper, we propose the use of the Kalker Book of Tables for Non-Hertzian Contact (KBTNH) in a case study addressing the feasibility of HiL testing of suspension components. In our tests, a bogie model incorporating a real yaw damper was used to assess the damper’s impact on vehicle stability. The assessments show that the model with the KBTNH contact algorithm not only significantly improves accuracy compared to the Vermeulen-Johnson algorithm but also remarkably reduces computing time compared to FASTSIM, demonstrating excellent performance in balancing accuracy and computational demands. Consequently, the KBTNH model is considered as an effective solution for meeting the challenging demands of real-time simulations and can be broadly applied in HiL testing and extended in the future to digital twin applications.