Abstract：The wheel-rail interaction has always been one of the most important research topics in the field of high-speed railway. And with the development of higher speed and larger axle-load for trains, the wheel-rail system will undergo plastic deformation during long-term service, resulting in the aggravation of wheel-rail rolling contact fatigue and damage, which seriously threatens the safety, stability and comfort of train operation. In the present work, a combined theoretical analysis and numerical simulation are conducted to study the elastic-plastic mechanical behavior of wheel-rail normal contact. Firstly, based on the Hertz contact theory and the bilinear hardening model, the elastic-plastic theoretical analysis model of wheel-rail normal contact was established, the wheel-rail elastic-plastic mechanical response characteristics were obtained, and the influence of axle load on contact pressure and contact deformation was discussed. Secondly, based on the three-dimensional wheel-rail contact finite element model, the wheel-rail contact mechanical behavior was simulated, and the theoretical error coefficient in terms of contact pressure and contact deformation was introduced to investigate the difference between the elastic and bilinear hardening models on the prediction results of the wheel-rail contact mechanics response, which verifies the reliability of the elastic-plastic theoretical analysis model of wheel-rail normal contact. It is found that the wheel-rail contact pressure and contact deformation increase with the increase of axle load. The theoretical error coefficient of the bilinear hardening model with regard to wheel-rail contact pressure and contact deformation is small, and the bilinear hardening model is accurate enough to predict the elastic-plastic mechanical behavior of wheel-rail normal contact, which can be used for further in-depth insight into the wheel-rail rolling contact elastic-plastic mechanical response characteristic. The obtained results can provide theoretical basis and technical support for the safe service and damage assessment of wheel/rail system.
2022, Vol. 43 
