高速铁路辙叉区钢轨打磨廓形设计方法

以心轨顶宽20、35、50 mm处的辙叉区钢轨关键截面作为研究对象，基于NURBS曲线理论建立辙叉区钢轨廓形重构方法；以关键截面钢轨廓形上若干型值点为设计变量，以打磨材料去除量的减少和脱轨系数的降低为目标，以钢轨廓形几何特征和降低钢轨滚动接触疲劳为约束条件，设计出18号道岔辙叉区钢轨经济性打磨廓形；建立了轮轨接触有限元模型和车辆-轨道耦合动力学模型，进行了轮轨接触应力与动力学指标计算。分析结果表明:优化的打磨廓形接触点分布均匀，具有良好的轮轨接触几何特性；钢轨打磨材料去除量在2号截面处降低了17.2%；各截面Mises应力分别降低了8.7%、8.3%和11.5%，轮轨接触应力降幅分别为12.9%、15.8%和18.0%；列车逆侧向过岔时，轮轨横向力与车体横向振动加速度分别降低了10.3%和15.6%，脱轨系数与轮重减载率分别降低了8.1%和10.6%，疲劳因子降低了12.2%。可见，优化廓形在保证列车运行安全性的同时，提升了列车运行的平稳性以及辙叉区钢轨的使用寿命。 

Design method of rail grinding profile in frog area of high-speed railway

For the critical section of a rail in the frog area with top widths of 20, 35 and 50 mm of the core rail as the research object, the rail profile reconstruction method was developed to analyze the frog area based on the NURBS curve theory. Several types of data points on the rail profile of the key section were set as design variables, and the reduction of the removal amount of grinding material and derailment coefficient were taken as the objective, and the geometric characteristics of the rail profile and the rolling contact fatigue reduction of the rail were used as constraints, the economic grinding profile of the rail in the frog area of No.18 turnout was designed. The wheel-rail contact finite element model and vehicle-track coupling dynamic model were established, and the wheel-rail contact stresses and dynamics indexes were calculated. Analysis results show that the optimized grinding profile contact points are evenly distributed and have good wheel-rail contact geometric characteristics. The removal amount of the rail grinding material decreases by 17.2 % in section 2. The Mises stresses of each section decrease by 8.7%, 8.3%, and 11.5%, respectively, and the wheel-rail contact stresses decrease by 12.9%, 15.8%, and 18.0%, respectively. When the train reversely passing turnout branch, wheel-rail lateral force and lateral vibration acceleration of the car body decrease by 10.3% and 15.6%, respectively, the derailment coefficient and the wheel-load reduction rate decrease by 8.1% and 10.6%, respectively, and the fatigue index decreases by 12.2%. Therefore the optimized profile not only ensures train operation safety, but also improves train operation stability and the service life of the rail in frog areas. 5 tabs, 14 figs, 26 refs.