高速动车组车下设备对车体振动传递与模态频率的影响机理研究

Study on the Effect of the Underframe Equipment on Vibration Transmissibility and Modal Frequency of the Car Body for High-speed EMU Trains

提出包含车下设备的高速动车组整备状态车体模态频率数值计算方法,并通过有限元分析及模态试验,验证该方法的准确性。理论研究车下设备对车体振动传递特性的影响,定义车体的名义垂向一阶弯曲模态频率,并结合数值计算、振动传递分析与模态试验分析,分析车下设备悬挂参数对车体模态频率的影响机理。研究表明,采用弹性吊挂的车下设备将与车体形成耦合振动系统,且耦合振动系统在原车体垂向一阶弯曲模态频率附近产生一个新的低频振动分量和一个新的高频振动分量;低频振动振型为车下设备垂向振动与车体垂向一阶弯曲振动同相,高频振动振型为二者反相振动;随着车下设备悬挂刚度的变化,车体的名义垂向一阶弯曲频率将会发生"频率跳变"现象。

A numerical method for calculating the modal frequency of a fully equipped high-speed electric multiple unit（EMU） train with the underframe equipment is proposed, and the method is verified by the finite element analysis and a modal test. The influence of the underframe equipment on the car body transmissibility is studied theoretically, the definition of the nominal car body first vertical bending frequency is given. Based on the numerical calculation, the analysis of vibration transmissibility and the modal experiment, the influence of the suspension parameter of the underframe equipment on the car body modal frequency is researched. Results show that the equipment and the car body will create a coupled vibration system with the equipment of elastic suspension, and new vibrations at a lower frequency and a higher frequency will be generated near the original frequency of the car body first vertical bending mode; the mode shape at the lower frequency is that the car body first vertical bending vibrates in phase with the equipment vertical movement, while the mode shape at the higher frequency is that they vibrate out of phase; with the changing of the suspension stiffness of the equipment, the first vertical bending frequency of the car body displays a frequency-hopping phenomenon.