高速车轮不圆顺的轮轨动态响应及损伤机理与规律研究

Out-of-round for wheel is an intrinsic damage phenomena of railway vehicles. It is significant in science and technology to investigate the dynamic wheel-track response and its damage mechanism and regulaties.Based on theoretical analysis, numerical simulation and experimental investigation, ranging from the level of constitutive relationship of materials to the level of structural response,the dynamic wheel-track response and damage mechanism of three types of out-of-round wheels (wheel flats, local defects and polygonization) will be studied in this proposal.The dynamic constitutive equations of base materials subjected to thermal-mechanical coupling fields will be derived firstly, and then the dynamic response of the wheel-track system for out-of-round wheels will be investigated theoretically,experimentally and numerically,respectively.Effects and affecting regulaties of key parameters on the characteristic response will be studied. On a consideration of coupling effect of the three elements,i.e. rolling contact fatigue damage,wear and plastic deformation, damage mechanism and evolutionary regulaties of wheel tread and rim will will be systematically explored, and the tolerances for wheel tread maintenance and safety management will be mastered.Present study may provide valuable gaidances to the match of wheel-track contact, wheel maintenance and safety management.

车轮不圆顺是铁道车辆车轮一种固有伤损现象，研究其轮轨冲击动态响应及其损伤机理与规律性具有重要的理论意义和工程价值。本项目拟采用理论分析、数值模拟和试验研究相结合的研究手段，从材料本构关系到结构响应的研究思路，研究高速车轮三种常见不圆顺形式（车轮扁疤、局部缺陷和多边形化）的轮轨动态响应及损伤机理与规律性；构建母材热-力耦合特性的动态本构关系，发展高速车轮不圆顺轮轨动态响应的理论分析模型，借助有限元方法模拟车辆-轨道系统的耦合动力学行为，分析关键参数对其特征动力学响应的影响规律；综合考虑滚动接触疲劳、磨损和塑性变形耦合损伤，研究踏面和轮辋损伤演变机制及规律性，确定车轮踏面与轮辋损伤维修与安全管理容限。为优化轮轨接触设计、材料匹配和车轮安全管理提供指导。

车轮不圆顺是铁道车辆车轮一种固有伤损现象，研究其轮轨冲击动态响应及其损伤机理与规律性具有重要的理论意义和工程价值。本项目采用理论分析、数值模拟和试验研究相结合的研究手段，开展了轮轨钢的动态力学特性及本构关系研究，发现了车轮钢的“第三类应变时效”现象，建立了轮轨钢动态本构关系；建立了含扁疤缺陷车轮-轨道系统的三维滚动接触有限元模型，系统表征了列车速度、扁疤长度和轴重等关键参量对轮轨冲击力学响应特征的影响规律，揭示了材料应变率效应抑制轮/轨塑性变形与热应力劣化轮/轨承载能力之间的耦合关系；针对车轮踏面剥离缺陷位置、尺寸和形状随机分布特点，将车轮踏面剥离引起的几何不平顺转换为轮轨接触界面的位移不平顺，建立了不同踏面缺陷情况下轮轨位移激励的数学模型，构建了轮轨接触耦合动力学响应的有限元仿真方法，系统研究了车轮踏面缺陷和多边形化引起的轮轨动态响应及损伤机理与规律，研发了轮轨接触随机不平顺的仿真分析软件。研究结果可为优化轮轨接触设计、材料匹配和车轮安全管理提供指导。

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