Investigation of wheel-rail wear reduction by using MRF rubber joints with bidirectional adjustable stiffness

Stiffness of the primary longitudinal rubber joints is critical for both the high-speed stability and curve trafficability of the train. However, existing joints with fixed stiffness inevitably generate large wheel-rail lateral forces and wear on curves. To address this issue, a fail-safe rubber joint incorporating magnetorheological fluid (MRF) technology is proposed, enabling bidirectional variable stiffness. First, the structure and working principle of MRF rubber joint are described in detail. Subsequently, prototypes of the MRF damper and the MRF rubber joint are assembled and tested, yielding satisfactory variable damping and stiffness performance. Moreover, dynamic simulations further demonstrate the joint’s effectiveness in improving both stability and curve trafficability. A control algorithm based on track curvature identification is also proposed. The co-simulation results validate the potential of the MRF rubber joint on reducing wheel-rail wear and enhancing safety of trains.