高速铁路道岔区钢轨接触疲劳伤损机理、成因和措施研究

During the operation of high speed railway, the rail fatigue defect of switch is obvious and influences the service life and operation safety of switch seriously. Therefore, a research on the mechanism, factors and control measures of contact fatigue defect of switch is of important theoretical significance and application prospect. Focusing on two scientific problems – wheel-rail contact relationship under complex time-space conditions, prediction and influencing factors of the development of fatigue crack and wear for high-speed switch. This project includes the following work which will be studied deeply and systematically: development characteristics of contact fatigue defect of switch, wheel-rail contact relationship under complex time-space conditions, mechanism of contact fatigue defect, prediction model, evaluation method and control measures. Systematic theoretical and experimental study will be carried out to reveal the generation and evolution mechanism of contact fatigue defect for high speed switch. A set of theory system with independent intellectual property will be established on wheel-rail contact fatigue defect of high speed switch, which can provide theoretical basis and scientific instruction for the design, operation and maintenance of high speed switch in our country.

在高速铁路运营条件下，道岔钢轨接触疲劳伤损显著，严重影响道岔使用寿命和列车运营安全。因此，进行高速道岔接触疲劳伤损机理、成因及控制措施的研究具有重要的理论意义和应用前景。课题针对高速道岔区复杂时空下的轮轨接触关系、高速道岔钢轨件疲劳裂纹与磨耗共生预测及影响因素两个关键科学问题，主要从高速道岔轮轨接触伤损发展特征、复杂时空下轮轨接触关系、岔区钢轨接触伤损机理、预测模型、评价方法与控制措施等方面进行深入、系统的研究。拟通过系统的理论及试验研究揭示高速道岔接触疲劳伤损产生与发展机理，形成一套具有自主知识产权的高速道岔轮轨接触疲劳伤损理论体系，为我国高速道岔的优化设计、运营安全与养护维修提供理论基础和科学指导。

我国高速铁路大规模运营条件下，道岔钢轨受到复杂的轮轨接触和荷载作用，其表面接触疲劳伤损显著，严重影响着道岔使用寿命和列车运营安全。.课题针对高速道岔复杂时空下的轮轨接触关系、道岔钢轨件疲劳裂纹与磨耗共生预测及影响因素两个关键科学问题，从高速道岔轮轨接触伤损特征和发展规律、复杂时空下轮轨接触关系和荷载水平、岔区钢轨接触伤损形成和发展机理及其预测方法、伤损评价方法与控制措施等方面进行了系统地研究。.研究掌握了高速道岔钢轨表面滚动接触疲劳伤损和磨耗共存的特征和发展规律；通过高速列车-道岔耦合动力学仿真分析和跟踪观测，研究了高速道岔区复杂时空下的轮轨接触关系，提出了高速道岔轮轨荷载谱，揭示了高速道岔条件下车辆过岔动态荷载转移情况和轮轨接触状态；采用实验室试验、现场跟踪观测和仿真预测，研究了道岔轮轨接触伤损形成和发展机理，再现了尖轨、心轨的滚动接触疲劳伤损和磨耗发展共存过程；提出了道岔区钢轨滚动接触疲劳裂纹-磨耗共生发展预测模型，预测了尖轨和心轨疲劳裂纹萌生寿命、萌生位置和发展规律；确定道岔区钢轨接触疲劳裂纹四等级评价方法，对不同级别应采取不同的裂纹控制措施。本课题的研究已经形成一套具有自主知识产权的高速道岔轮轨接触疲劳伤损理论体系，为我国高速道岔的优化设计、运营安全与养护维修提供理论基础和科学指导。