A semi-online spatial wheel-rail contact detection method

Online spatial wheel-rail contact detection with elastic contact hypothesis has a heavy computational burden. The traditional end-to-end look-up table method can significantly improve search efficiency. However, It has high storage requirements. In this paper, a semi-online approach is proposed to alleviate the contradiction between the online and the offline method. First, a new algorithm of normal maximum penetration for unworn rail profiles is proposed. The algorithm is only required to calculate the closest proximity of the rail feature point to the wheel contact trace contact curve. Then, derived curves with different yaw angles are pre-stored in a new look-up table for online dynamics simulation usage. The proposed look-up table reduces the required generation time and the storage space. The numerical simulation results show that the proposed method can be used for train dynamics simulation under earthquakes. Besides, the search speed is much faster than that of the online method.