大准铁路小半径曲线钢轨打磨廓形及工艺研究

Study on Grinding Prof ile and Technology for Sharp Curve Rail of Dazhun Railway

针对大准铁路小半径曲线钢轨伤损和磨耗严重开展钢轨打磨技术研究,进行打磨模板设计。本文通过分析实测轮轨廓形的磨耗和接触特征,确定钢轨打磨目标廓形,据此设计得到适合于大准铁路小半径曲线的钢轨打磨廓形,并采用重载货车-轨道动力学模型和轮轨接触有限元模型进行理论计算与分析。结果表明:车轮与实测钢轨廓形匹配时,上股易形成过共形接触,下股接触点偏向轮缘根部,形成反向轮径差,降低曲线通过性能;车轮与打磨廓形匹配时轮轨接触状态得到明显改善,轮对冲角、轮轨横向力、脱轨系数、磨耗指数和轮轨接触应力均显著降低,大幅提高了曲线通过性能。

According to the rail severe fatigue and wear occurred in sharp curve rail of Dazhun railway,rail grinding technology was studied and the grinding template was designed.The wear and contact characteristics of measured wheel-rail prof iles were analyzed,the target prof ile of rail grinding was determined,a rail grinding prof ile suitable for sharp curve of Dazhun railway was obtained based on this design,and theoretical calculation and analysis was carried out by using heavy haul freight car-track dynamic model and wheel-rail contact f inite element model.The results showed that when the wheel matches with the measured rail prof ile,the upper strand is liable to form hyperconformal contact,and the lower strand contact point deviates to the root of the wheel f lange and forms a reverse wheel diameter difference,which reduces the curve passing performance.The wheel-rail contact state is improved obviously when wheel matches with grinding prof ile,wheel attack angle,wheel-rail transverse force,derailment coeff icient,wear index and wheel-rail contact stress decreases signif icantly,which improves the curve passing performance signif icantly.