A Novel Method to Search for the Wheel-Rail Contact Point

This paper proposed the normal contact searching method (NCSM), a novel method to search for the wheel-rail contact point, which utilizes the normal maximum penetration distance between wheel and rail as the judgment condition. The contact point found by the NCSM can better represent the center of the wheel-rail contact patch which is considered more reasonable than the commonly used vertical contact searching method (VCSM), the latter adopts the vertical minimum distance to determine the wheel-rail contact point. The differences between these two methods are analyzed and compared for the same contact point situation and with same motion parameters. The results show that, for the Chinese LMA wheelset and CHN60 rail profiles, these two methods have slight differences for the same contact point situation. For a wheelset with a lateral displacement less than 7.0 mm and with no yawing, the NCSM's contact point is very close to VCSM's, so both methods are suitable for the dynamic calculation. For a wheelset with a lateral displacement greater than 7.0 mm or with yawing, an unreasonable jump occurs at the wheel-rail contact point and wheelset angle root contact by applying VCSM, while the NCSM has only small discrete jump on the wheelset tread contact. In this case, the NCSM instead of VCSM should be used in the dynamic analysis.