This paper describes and compares the use and limitations of two constraint-based formulations for the wheel–rail contact simulation in multibody dynamics: (1) the use of contact lookup tables and (2) the Knife-edge Equivalent Contact constraint method (KEC-method). Both formulations are presented and an accurate procedure to interpolate within the data in the lookup table is also described. Since the wheel–rail constraint contact approach finds difficulties at simultaneous tread and flange contact scenarios, the lookup table method is implemented with a penetration-based elastic contact model for the flange, turning the method into a hybrid (constant in the tread and elastic in the flange) approach. To deal with the two-point contact scenario in the KEC-method, a regularisation of the tread–flange transition allows the use of the constraint approach in the tread and also in the flange. To show the applicability and limitations of both methods, they are studied and compared with special emphasis in the calculation of normal and tangential contact forces. Numerical results are based on the simulation of a two-wheeled bogie vehicle in different case studies that consider irregular tracks and two wheel–rail profiles combinations: profiles that do not show two-point wheel–rail contacts and profiles that do show two-point wheel–rail contacts. Although results show a good agreement between both approaches, the use of the KEC-method is more extensive since it allows to reproduce the wheel-climbing scenario that cannot be simulated with the lookup table method with the hybrid contact approach. It is concluded that simulations with this later method may not be on the safe side.

本文描述并比较了两种基于约束的公式在多体动力学中的轮轨接触仿真的使用和局限性：（1）使用接触查找表和（2）刀沿等效接触约束方法（KEC-方法）。给出了两种公式，还描述了在查询表中的数据内插的准确过程。由于轮轨约束接触方法在同时进行胎面和法兰接触时会遇到困难，因此使用基于渗透的法兰弹性接触模型来实现查找表方法，从而将该方法转变为混合（在胎面中恒定，在胎面中为弹性法兰）方法。为了处理KEC方法中的两点接触方案，胎面-法兰过渡的正则化允许在胎面以及法兰中使用约束方法。为了显示这两种方法的适用性和局限性，在法向和切向接触力的计算中对它们进行了研究和比较，并特别强调了它们。数值结果基于两轮转向架车辆在不同案例研究中的仿真，这些案例研究考虑了不规则的轨道和两个轮轨轮廓的组合：不显示两点轮轨接触的轮廓和显示两点的轮廓轮轨接触。尽管结果表明这两种方法之间具有良好的一致性，但是KEC方法的使用更为广泛，因为它允许重现无法用混合接触方法的查找表方法模拟的车轮爬升情况。