高速铁路道岔区轮轨接触行为演变规律与动态组合廓形优化研究

Contact trajectory on rail surface can be regarded as the mathematical description of the continuous ribbon space surface produced by the single rolling contact process of a wheel on rail. It directly maps the wheel/rail relation and effectively reflects the multi-level information of the wheel/rail contact state, so it can be used as an important yardstick to measure the high-speed wheel/rail contact behavior and matching relationship. Looking into the current important and difficult issues of wheel/rail match in high-speed railway turnout with a new perspective, extensive surveys for the running band of rails in high-speed turnouts are carried out to explore the incidence relationships between the running bands and contact trajectories; the factors which affect the wheel/rail contact state in turnout zone are analyzed. A contact trajectory spatial distribution analysis model is established within consideration of dynamic combined rail profile in turnout zone, meanwhile, the wheel/rail contact form is obtained by solving the multi-point non-Hertzian contact problem, so the macro spatial distribution and microscopic form of contact trajectory on rail surface can be collected accurately. And then the quantitative description and evaluation methods of contact trajectory on rail surface are proposed to study the influence mechanism and evolution rule of wheel/rail contact behavior; a multi-objective optimization model for dynamic combined rail profile in turnout is also established and solved, to achieve comprehensive optimization of dynamic combined rail profile and to provide scientific guidance for the development of high-speed turnout with a design speed of 400km/h and the maintenance of more than 5000 in-service high-speed turnouts.

钢轨表面接触轨迹是列车车轮在钢轨表面单次滚动接触运行所产生的连续带状空间曲面的数学描述，能与轮轨关系形成直接映射关系、有效反映轮轨接触状态的多层次信息，可作为衡量高速轮轨接触行为和匹配关系的重要标尺。以崭新视角切入当前所面临的高速道岔轮轨接触、匹配重难点问题，开展高速道岔钢轨表面光带的广泛调研，探索光带与接触轨迹间的关联关系并进行岔区轮轨接触状态影响因素分析；构建可考虑组合廓形动态特性的道岔钢轨表面接触轨迹空间分布分析模型，求解轮轨多点非赫兹接触问题得到岔区轮轨接触形态，实现钢轨表面接触轨迹宏观空间分布与细观形态综合信息的准确获取；提出钢轨表面接触轨迹定量描述与评价方法，探明高速道岔轮轨接触行为的影响机理及演变规律；建立并求解道岔钢轨动态组合廓形多目标优化数学模型，实现基于多目标最优的高速道岔动态组合廓形综合优化，为400km/h高速道岔的研发和5000多组在役高速道岔的维护提供科学指导。

道岔是高速铁路线路的薄弱环节及养护维修的难点，其钢轨表面接触轨迹是列车车轮在钢轨表面单次滚动接触运行所产生的连续带状空间曲面的数学描述，能与轮轨关系形成直接映射关系、有效反映轮轨接触状态的多层次信息，可作为衡量高速轮轨接触行为和匹配关系的重要标尺。针对钢轨表面接触轨迹的分析理论与评价方法不成熟、道岔区轮轨接触行为的影响机理及演变规律不明确、道岔区轮轨廓形动态匹配不合理的工程问题，开展了系列研究并取得以下成果：①研发了轨道钢轨光带移动式检测小车，构建了光带小车相机标定、图像滤波、信息识别、异常值处理算法；建立了轮轨接触状态长期观测试验段，挖掘了道岔钢轨表面接触轨迹与道岔运营条件的映射关系，辨识了道岔轮轨接触状态的典型影响因素。②考虑轮对和道岔柔性变形，编制了车辆-道岔刚柔耦合动力学计算程序，提出了道岔区钢轨件三维廓形精确数学描述方法，筛选了适用于道岔区的非Hertz轮轨接触模型，构建了高速道岔钢轨表面接触轨迹综合分析模型；实现了轮载过渡时钢轨组合廓形动态重构和轮轨冲击的精细高效模拟，以及钢轨表面接触轨迹宏观分布与接触斑细观形态的定量描述。③基于接触轨迹的中心线、宽度和间隙三个特征指标，结合峰值管理和均值管理，建立了高速道岔钢轨表面接触轨迹评价方法。通过动力学仿真，分析了轮轨关系演化典型因素对道岔区轮轨接触行为的影响规律。④以NURBS方法参数化描述道岔钢轨空间廓形，根据道岔实际服役条件构建了优化目标函数；基于代理模型法，建立了道岔服役性能与动态组合廓形的映射关系；基于非支配排序遗传算法NSGA-II，获取了综合性能最优的道岔钢轨组合廓形，开发了高速道岔钢轨打磨目标廓形设计软件。上述成果为第二代高速道岔的研发提供了科学指导，所研发的光带小车弥补了轨道交通领域光带检测的技术空白，所开发的高速道岔钢轨打磨目标廓形设计软件为在役高速道岔的科学打磨提供了技术支撑。