【作者】 陈东；

【导师】 邬平波；

【作者基本信息】 西南交通大学 ， 车辆工程， 2019， 硕士

【摘要】 高速运行的动车组车体所受到的载荷复杂,车下设备刚性吊挂使车体承载更加恶劣,可能引发局部结构的疲劳失效,对动车组车下吊挂局部承载结构疲劳强度的研究显得越来越重要。本文基于动力学和疲劳强度结合的分析系统方法,对服役条件下动车组车下吊挂局部疲劳强度进行了相关研究。本文建立了整备状态下的动车组车体有限元模型,通过与实测模态振型数据的比对,修正了该模型,获取了车体主结构的各阶模态振型,以及横梁局部结构的各阶模态振型。对车下吊挂设备安装的车体横梁上相关载荷施加点,分别施加单位静态载荷和扫频载荷,进行准静态分析和谐响应分析,得到对应载荷工况下的准静态响应函数和频响函数。结合京沪线实际线路工务图信息,对线路全程进行工况的划分,以直线、曲线、道岔、牵引、制动工况进行组合,基于线路实测振动加速度数据验证后的刚柔耦合动力学模型,以仿真分析手段获取各个工况下车体的悬吊设备吊挂点位置的时域载荷,并通过相应的实际线路里程进行线性扩展,编制线路全程的载荷谱。该载荷谱可作为服役条件下动车组车下吊挂局部疲劳强度研究的基础。本文还以准静态响应函数和频率响应函数作为传递函数,以载荷谱作为输入变量,结合材料S-N疲劳特性曲线,借助于Miner损伤累积法则对吊挂局部的疲劳强度进行了研究,并且对准静态法、模态叠加法和时频法结果进行了对比。基于上述动力学和疲劳强度结合的分析系统,本文考虑车轮踏面在不同磨耗条件下,以及动车组失稳等故障工况下,对刚性吊挂和弹性吊挂下的吊挂局部疲劳强度进行了对比分析,结果表明,刚性吊挂较弹性吊挂会造成吊挂点局部和横侧梁连接位置更大的损伤。更多还原

【Abstract】 The load on the high-speed EMU carbody is complicated,and the rigid equipment hanging under the vehicle makes the vehicle body load more severe,which may cause fatigue failure of the local structure.It is becoming more and more important to study the fatigue strength of the local load-bearing structure of the lower suspension of EMU.Based on the analysis system method combining dynamics and fatigue strength,this paper studies the local fatigue strength of the EMU under the service conditions.In this paper,the finite element model of the carbody under the condition of the preparation is established.The model is modified by comparison with the tested mode,and the modes of the structure of the carbody and the local structure of the beam are obtained.Each mode of mode shape.Applying the static load and sweeping load to the relevant load on the vehicle body beam installed on the under-hanging equipment,and performing quasi-static analysis and harmonic response analysis to obtain the quasi-static response function and frequency response function under the corresponding load conditions.Refering to the actual line drawing information of the Beijing-Shanghai line,the whole line is divided into several parts,including straight line,curve,ballast,traction and braking conditions.The rigid-flexible coupling dynamics model is verified based on the measured vibration acceleration data of the line.The time domain load of the suspension position of the suspension body of the vehicle body under each working condition is obtained by simulation,and the load spectrum of the whole line is compiled by linear expansion of the corresponding actual line mileage.The load spectrum can be used as the basis for the study of the local fatigue strength of the undercarriage of the EMU carbody under service conditions.In this paper,quasi-static response function and frequency response function are used as transfer functions,load spectrum is used as input variable,combined with material SN fatigue characteristic curve,and the fatigue strength of hanging part is studied by Miner damage accumulation rule,and the static state is aligned.The results of the method,the modal superposition method and the time-frequency method are compared.Based on the above analysis system combining dynamics and fatigue strength,this paper considers the wheel tread under different wear conditions and the unstable conditions of the EMU,and the local fatigue strength of the suspension under rigid suspension and elastic suspension is carried out.Comparative analysis shows that the rigid suspension is more elastic and will cause more damage to the joint position of the hanging point and the lateral beam.更多还原