基于ALE有限元的轮轨稳态滚动接触分析

Wheel-Rail Steady State Rolling Contact Analysis Based on ALE Finite Element Method

基于Arbitrary Lagrangian Eulerian (ALE)有限元方法建立稳态轮轨滚动接触的三维有限元模型。该模型用接触面上相对滑移速度定义轮轨滚动接触的黏着和蠕滑条件,并在虚功率方程中通过Lagrange乘子法引入接触界面上无切向滑移约束,更好地计算分析接触斑的黏着特性。该模型不但可以考虑材料、几何和接触非线性问题,还可以考虑车轮滚动速度、轮轨的实际几何形态以及惯性力的影响,并能分析接触斑的接触应力和相对滑移速度的分布情况。用该模型对单轮对在轨道上稳态滚动时的接触状态分析表明:基于该模型计算得到的轮轨滚动接触的接触斑形态和Hertz理论的椭圆假设有较大差别;通过相对滑移速度来描述接触斑滑动和黏着状态,更有利于描述轮轨的相互作用;明显观察到接触斑里的摩擦力分布和相对滑移速度的自旋效应;接触斑里摩擦力的旋转分布对轮轨系统的振动、轮轨的黏着和磨损的产生有较大影响。

Based on the Arbitrary Lagrangian Eulerian （ALE） FEM, 3D FE model for the steady-state wheel-rail rolling contact has been established. This model uses the relative sliding speed on the contact surface to define the adhesion and creep conditions of the wheel-rail rolling contact, and introduces the non-tangential sliding constraint on the contact interface into the equation of reactive power by means of the method of Lagrange multipliers, so as to better calculate and analyze the adhesion characteristics of the contact patterns. This model not only takes into considerations of the material, geometry and the problem of non-linear contact, but also takes into account of the wheel rolling speed, the actual geometrical shape and the influence of the inertia force, and simultaneously analyzes the contact stress of the contact patterns and the distribution of the relative sliding speed. The analysis on the contact status of the mono-wheel roll- ing on the rail under the steady state demonstrates that the contact pattern shape for wheel-rail rolling contact obtained by this model differs greatly from the Hertz theory-based elliptical assumption. To describe the sliding and adhesion status of the contact patterns by means of the relative sliding speed is more helpful to describe the mutual effect of wheel and rail, and also the frictional force distribution inside the contact pattern and the spin effect of the relative sliding speed can be obviously observed. The rotation and distribution of the frictional force inside the contact pattern has a huge impact on the wheel-rail system in the aspects of the vibration, the adhesion and the generation of wear.