实测轮轨蠕滑曲线对钢轨磨耗影响分析

Effect of Measured Wheel-Rail Creep Curves on Rail Wear

轮轨蠕滑曲线会影响轮轨动态相互作用,进而影响钢轨磨耗,为研究实测轮轨蠕滑曲线对钢轨磨耗的影响,首先,基于最小二乘法获得适用于Polach模型和修改FASTSIM算法的参数,模拟40~400 km/h行车速度范围内的实测蠕滑曲线;随后,在SIMPACK软件中建立车辆系统动力学模型,并通过Polach模型测得实测蠕滑曲线;最后,采用Kik-Piotrowski模型和修改的FASTSIM算法进行轮轨非赫兹滚动接触计算,并结合USFD磨耗模型预测钢轨磨耗,对比了理想与实测蠕滑曲线条件下钢轨磨耗的差异.研究表明:理想蠕滑曲线条件下钢轨磨耗深度明显大于实测蠕滑曲线下的结果,随着车辆通过次数的增加,理想条件下钢轨磨耗分布范围更大,内外轨磨耗分布范围分别为实测蠕滑曲线的1.5倍和1.3倍;摩擦系数和磨耗率显著影响钢轨磨耗大小及磨耗分布情况,故在车辆动力学仿真和钢轨磨耗计算中有必要考虑实测轮轨蠕滑曲线;形成了确定实测蠕滑曲线参数的前处理程序,可服务于车辆动力学仿真和钢轨磨耗计算,可以有效指导现场进行钢轨打磨等养护维修工作.

The wheel-rail creep curve influences dynamic wheel-rail interaction,which further affects rail wear.To study the effect of the measured wheel-rail creep curve on rail wear,parameters suitable for the Polach model and modified FASTSIM algorithm were obtained based on the least square method,and measured creep curves at the running speed of 40–400 km/h of the vehicle were simulated.After that,the vehicle system dynamics model was established in the SIMPACK,and measured creep curves were considered through the Polach model.Finally,the Kik-Piotrowski model and modified FASTSIM algorithm were used to calculate the non-Hertzian rolling contact,and rail wear was predicted by the USFD model.The discrepancies of rail wear under ideal and measured creep curves were compared.The research shows that the rail wear depth under the ideal creep curve is more obvious than that under the measured creep curve.As more vehicles pass the rail,the rail wear distribution range under ideal conditions is larger,and the distribution ranges of inner and outer rail are respectively 1.5 and 1.3times those under the measured creep curve;the friction coefficient and wear rate significantly influence the magnitude and distribution range of rail wear,so it is necessary to consider the measured wheel-rail creep curve in vehicle dynamics simulation and rail wear calculation.A pre-processing program is developed to determine parameters of the measured creep curve,which can serve for vehicle dynamics simulation and rail wear calculation and effectively guide maintenance work such as rail grinding.