复杂激励下高速动车组齿轮传动系统动力学分析与箱体微裂纹识别

High-speed EMUs gear system has strong nonlinearity due to its characteristics such as time-varying mesh stiffness and transmission error, etc. The gear system presents more complicated dynamic behaviors under external excitations, for example, track irregularity, wheel-rail impact, etc. These dynamic behaviors cause the problems such as gear failure and gearbox rupture, which will seriously influence the train operation safety. Therefore, it is urgent to master the evolution of nonlinear dynamic behavior of gear system: Firstly, this project would start from the typical external and internal excitation studies of the gearbox, and the multi-degree-of-freedom dynamics model for the coupling of helical gear-shaft-bearing-case is established based on the improved subsystem synthesis method to study the dynamic characteristics of gear system under typical external and internal excitations; what’s more, the rigid-flexible coupling finite element model of the helical gear-shaft-bearing-box is established for verifying the results listed above. Secondly, the above-mentioned finite element model is used to study the dynamic characteristics of the gearbox under the excitation caused by gear failure. Multi-excited gear transmission experiments are adopted to verify the theoretical results of the influence of gear system dynamic behavior on the gearbox dynamic characteristics, and then the crack position of the gear box would be deduced and its life predicted. Finally, the acoustic emission technique used to identify the micro-cracks in the box will be studied, including the positioning technique on the structure of paint layer and ribbed slab on its surface and the signal noise reduction and characteristic signal enhancement technology under strong noise, thus our research team will develop a set of online monitoring and warning system for High-speed EMUs gearbox crack.

高速动车组齿轮传动系统因具有时变啮合刚度、传递误差等特征表现出强非线性，又受到轨道不平顺、轮轨冲击等外部激励作用，呈现出更加复杂的动力学行为，引发齿轮故障与箱体破裂等问题，严重影响列车运行安全，因此亟需掌握齿轮传动系统非线性动力学行为演化规律。本项目首先从齿轮箱内外部典型激励研究入手，改进子系统综合法建立斜齿轮-轴-轴承-箱体耦合的多自由度动力学模型，研究在内外部典型激励下系统的动力学特性，并建立斜齿轮-轴-轴承-箱体的刚柔耦合有限元模型予以分析验证；其次采用该有限元模型研究齿轮故障引发激励下的箱体动态特性，并进行多种激励的齿轮传动实验以验证系统动力学行为对箱体动态特性影响的理论结果，进而推演箱体易发裂纹部位及预测寿命；最后研究识别箱体微裂纹的声发射技术，包括带涂层与肋板结构的声源定位定性技术、强噪音下信号降噪和特征信号增强技术，研发高速动车组齿轮箱箱体裂纹在线监测和预警系统。

高速动车组齿轮箱因具有时变啮合刚度等特征表现出强非线性，并受到轨道不平顺等激励作用，从而引发更加复杂的动力学行为，容易引发齿轮故障与箱体破裂等问题，势必影响列车的安全运行。本项目针对内外部激励下高速动车组齿轮传动系统的复杂动力学行为以及齿轮箱故障开展研究，主要内容包括：建立了高速列车齿轮传动系统的动力学模型，得到了基于IHBM法的齿轮传动系统解析解，探讨了驱动端、负载端的激励频率与幅值以及轮齿裂纹等故障激励对系统动力学特性的影响规律；建立了涵盖斜齿轮-轴-轴承-箱体-转向架-列车的齿轮传动系统动力学仿真模型，掌握了内外部激励下齿轮箱振动响应规律，探明了多工况下箱体振动显著部位与应力集中区域；分析了对齿面磨损、断齿、箱体裂纹、轴承伤损等故障工况下齿轮箱振动响应和动应力，掌握了齿轮传动系统动力学行为对箱体动态响应和动力稳定性的影响规律；提出了箱体多层介质的声发射平面波倾斜入射模型，分析了涂层参数对声发射波波速和能量的影响规律，发明了基于幂函数的声发射源定位方法；构建了双目立体视觉齿轮箱箱体表面检测系统，实现了基于点云切片与区域提取的箱体缺陷检测。