轮对自激振动激扰的机车振动特性研究

The high speed and heavy load of railway transportation make the dynamic interaction between the locomotive-wheel and rail grow, so as to the vibration and the problem of wheel wear and abrasion become more serious. The traditional theory and method can't fully elucidate the mechanism, resulting in the treatment effect still need to be improved. A new source of locomotive excitation is put forward in this project, which is the self-excited vibration of locomotive wheel. From the perspective of mechanical system and the electromechanical coupling, using energy principle and internal feedback mechanism, the mechanism of locomotive wheel self-excited vibration will be elaborated. A dynamics analysis model of locomotive wheel self-excited vibration will be established, so as to study the condition and stability judgment of self-excited vibration. In addition, the characteristics and influencing factors of self-excited vibration will be analyzed. The locomotive dynamics analysis model including wheel self-excited vibration also will be presented by the modular modeling technology, so as to study the locomotive vibration characteristics by excitation due to the wheel self-excited vibration. In order to put forward the principle and measures to avoid resonance, the coupling vibration effect among wheels, frame and car-body of locomotive will be done. The response and effect between the locomotive vertical high-frequency vibration and the locomotive longitudinal relaxation vibration caused by wheel self-excited are studied. The new mechanism of the wear and abrasion of locomotive wheel is analyzed. What's more, to verify the reliability of the theoretical model and the accuracy of the simulation analysis, many test research will be done. At the same time, the way and related technical measures to reduce the dynamic interaction between wheel and rail are presented.

我国铁路运输繁忙，服役机车负荷饱满，使得机车轮轨相互作用日益增强、振动加剧、车轮磨损磨耗问题突出。传统理论和方法不能完全阐明其机理，治理效果还需提高。本课题提出机车存在一种新的激扰源，它是机车轮对的自激振动。将从机械系统和机电耦合角度，利用能量原理和内在反馈机制，阐述轮对自激振动的机理；建立轮对自激振动动力学分析模型，研究轮对自激振动的产生条件和稳定性判定，分析轮对自激振动特性及影响因素。还将通过模块式建模，建立包括轮对自激振动模型在内的机车动力学分析新模型，研究轮对自激振动激扰的机车振动规律；研究轮对、构架、车体之间的耦合振动作用关系，提出避免共振的原理和措施；研究机车垂向高频振动和机车纵向张弛振动作用及效果，分析机车轮对磨损磨耗新机理。并开展试验研究，验证理论模型的可靠性及仿真分析的准确性。同时，在应用上，提出进一步减轻轮轨动态相互作用的途径及相关技术措施。

对轮对自激振动问题的研究，探知了轮对自激振动产生的机理；分析了轮对自激振动下驱动系统扭-纵耦合振动特性；研究了轮对自激振动对高速动车的影响，进行了系统参数对轮对自激振动作用效果的影响分析，提出了抑制/减小轮对自激振动影响的措施；并开展了驱动系统悬挂参数对机车轮对恢复粘着性能的仿真及试验验证。将自激振动的理论引入轨道交通领域，拓展了机车动力学的理论。研究成果可为减小/抑制轮对自激振动的产生，机车驱动系统在设计时降低轮对自激振动带来的影响提供理论依据及途径。.对系统响应的振动测试数据分析的研究，提出了一种基于形态滤波、能量原理和特征IMF选择的改进EMD方法，可用以消除模态混叠现象、提取潜在的故障信息；同时，提出一种二次频率耦合的对角切片谱的分析方法，拓展了对角切片谱的应用。.由于轮对自激振动是由于轮轨界面接触产生的激扰而激发的，基于界面激扰这个概念和思路，项目对研究计划进行了一定扩展，并研究了驱动系统内部齿轮副啮合界面激扰和轮轨界面几何误差激扰等内容。.对驱动系统内部齿轮副啮合界面的激扰问题的研究，提出了在齿宽方向具有非均匀分布的齿根裂纹的齿轮啮合刚度计算模型；基于势能原理建立了具有齿廓变位的内啮合齿轮副的啮合刚度计算模型；采用多尺度法分析了齿面啮合激扰引起的时变刚度下机车驱动系统的稳定性；进而研究了齿面摩擦对驱动系统稳定性的影响。可为齿轮界面激扰的精确模拟提供方法，为提高驱动系统的稳定性提供理论依据。.对轮轨界面几何误差激扰问题的研究，分别仿真分析了轨道平顶型、隆起型、连续交点型、正弦型、指数衰减型局部激扰以及局部不平顺的恶化对机车动力学性能的影响。可为机车在运行中减小危害，提高运输安全水平提供参考依据。