两种轮轨接触应力算法对比分析

选择我国高速车轮LMa踏面及其运营磨耗后实测得到的踏面外形与我国标准CN60钢轨匹配，分别采用三维弹性体非Hertz滚动接触理论及其数值程序CONTACT和三维轮轨接触有限元模型，计算了轮轨接触斑面积、接触压力和接触应力等，并对两种算法所计算的结果进行了对比分析。计算结果表明:CONTACT程序计算得到的轮轨接触斑面积小于有限元计算结果，但CONTACT计算得到的轮轨间最大接触压力和最大等效应力大于有限元结果，尤其在车轮轮缘贴靠钢轨时两者差异更为明显。而当车轮与钢轨在接触点处的曲率半径远大于接触斑的几何尺寸时，CONTACT和有限元法得到的结果差异较小。车轮磨耗后轮轨接触容易发生多点接触，CONTACT和有限元法计算轮轨多点接触得到的结果相差非常大，CONTACT程序不宜用来解决此类接触问题。

COMPARATIVE ANALYSIS OF TWO ALGORITHMS FOR WHEEL-RAIL CONTACT STRESS

The comparative analysis of Kalker’s theory of three-dimensional elastic bodies in the rolling contact with non-Hertzian (CONTACT) and the finite element method is conducted. These two algorithms were used to calculate the contact area, the contact pressure and contact stress of wheel and rail. In the investigation, the wheel profile LMa used in the high speed train of China (CRH2) and its worn profile measured after a running of 100000 kilometers are chosen to match with 60kg/m rail of China. The results show that the wheel-rail contact area calculated by CONTACT is less than that calculated by the finite element method (FEM), but the maximal contact pressure and maximal equivalent stress calculated by CONTACT are larger than those calculated by FEM, especially when the wheel flange contacts with a rail gauge corner. The difference between the results of CONTACT and FEM is very small when the significant dimensions of the contact area are small, compared with the relative radii of curvature of wheel and rail at the contact point. Multi-contact is easy to occur when worn wheel profile contacts with a rail profile. The difference between the results of CONTACT and FEM is significant when multi-point contact occur. Therefore, CONTACT is not suit for the case of the multi-point contact of wheel and rail.