A Non-Iterative Wheel-Rail Contact Geometry Determination Algorithm and Its Application

To ensure a more accurate simulation of the wheel-rail contact state in vehicle-track interaction, a non-iterative contact geometry determination algorithm is proposed. This algorithm decouples lateral movement and roll, independently calculates the minimum wheel-rail gap on both sides, and overcomes the limitation of simultaneous wheel-rail contact on both sides. It can be applied to single-side and two-side wheel-rail separation problems. Additionally, by converting track irregularity and rail deformation into the reverse displacement of the wheel, it avoids real-time calculation of the wheel-rail spatial position, thereby improving calculation efficiency. The effectiveness of the algorithm is verified through Universal Mechanism software and field measurements. Subsequently, the influence of the measured wheel-rail profile, rail cant, and rail gauge on the wheel-rail contact characteristics is analyzed. Finally, vehicle shaking caused by track irregularity and wheel-rail contact is examined from the perspective of wheel-rail matching. The study demonstrates that the non-iterative algorithm is suitable for online simulation by pre-processing the contact geometry parameters. When the track gauge and rail cant increase, the distribution of wheel-rail contact points becomes more concentrated. Furthermore, when the excitation frequency of wheel-rail matching is close to the track irregularity excitation frequency, it causes vibration amplification, resulting in lateral vehicle shaking.