钢轨—车轮修复加工表面完整性设计和对偶匹配研究

Facing the fundamental and common problems in steel rail and train wheel maintenance field, such as: the lack of specification on rail and wheel machined surface integrity; the lack of selection basis on machining process and parameter of rail grinding and the wheel turning; the lack of rail and wheel surface structure matching specifications corresponding high-speed passenger transport and heavy freight transport; the lack of rail and wheel material constitutive relation, etc., to develop the new research. Facing the special processing conditions corresponding the preventive and corrective maintenance grinding of high-speed passenger transport or heavy freight transport railway, as well wheel repair machining, present the machined surface initiative design concept and basis for rail and wheel machining; design and carry out a large number of experiments, acquire the thermal physical property data and dynamic characteristic data of rail and wheel material, build the rail and wheel material constitutive model; through experiment and finite element simulation, obtain the design basis of grinding wheel and cutting tool as well the processes corresponding preventive and corrective maintenance machining respectively; put forward the reasonable matching of rail and wheel surface structures; set up the mapping relation between the noise signal of repaired wheel —rail frication and the wear type and degree of surface coupling.

面向轨道交通行业列车运行轮—轨维护前沿领域目前存在的根本性、共性问题：缺乏对钢轨和车轮机加工后表面完整性要求规范；对不同程度损伤钢轨打磨、车轮镟修工艺方式和参数选择缺乏依据；缺乏对应高速客运和重载货运的钢轨与车轮表面结构匹配规范；缺乏钢轨和车轮材料本构关系等，开展填补空白性和补充性研究。对应高速客运预防性打磨或重载货运铁路钢轨的修复性打磨机加工以及车轮修复机加工的特殊性工况，提出钢轨和车轮加工表面完整性主动设计概念和依据；设计和实施大量实验，获取钢轨、车轮主要材料从室温到加工范围内高温的热物性和动态特性数据，建立钢轨和车轮材料本构模型；通过实验和有限元模拟，获取预防性和修复性打磨加工钢轨以及镟修车轮的砂轮、刀具设计和加工工艺设计依据，提出修复钢轨与车轮表面结构合理匹配，建立修复后的车轮和钢轨对磨噪声信号特征与耦合组表面损耗类型和程度的映射关系。

本项目面向钢轨铣-磨修复及车轮镟修并密切围绕轮/轨材料高温动态力学性能分析及本构模型建立、钢轨铣-磨专用试验台的自主研制、钢轨铣-磨力热特性及表面完整性变化规律、车轮车削力热特性及表面完整性变化规律以及机加工后轮/轨对偶匹配等目前亟需解决的关键核心问题开展了系统性研究：实验研究U71Mn 钢轨材料在高温和大应变率条件下的动态力学性能，并探讨了钢轨材料的应变硬化、应变率和温度敏感效应及微观组织演化规律，建立和修正了钢轨材料的原始 Johnson-Cook本构模型；以钢轨铣-磨应用工况为设计参考并自主研发和搭建出钢轨铣-磨专用实验台，建立了钢轨成形铣削力模型和成形磨削力模型，基于线热源法分别建立了钢轨成形铣削温度场模型、成形磨削温度场模型及铣-磨联合温度场模型；通过实验分别探究了U71Mn钢轨材料成形铣削和和成形磨削表面完整性变化规律并对其进行了机理分析，基于人工神经网络分别建立了钢轨成形铣削和成形磨削的表面粗糙度预测模型；通过车轮材料车削实验分析了切削参数对车轮材料切削力与刀具切削温度的影响规律和开展了车轮材料车削表面完整性实验研究；从摩擦系数、磨损量、亚表面塑性变形层和磨损表面形貌等方面详细分析了机加工后轮/轨材料表面完整性对摩擦磨损特性的影响规律。