车下设备对车体振动的影响

为了考虑车体的弹性振动, 将车体等效成欧拉伯努利梁, 建立了车体与设备垂向耦合振动模型, 研究了车下设备刚性悬挂与弹性悬挂对车体振动幅频特性的影响。基于模态叠加法原理建立了考虑车体弹性振动和车下设备的高速动车组三维刚柔耦合动力学模型, 分析了车下设备悬挂方式、重心偏载与弹性悬挂参数对车体振动响应的影响规律。采用欧拉伯努利梁模型的数值分析结果表明:基于动力吸振器原理, 当车下设备采用合理的弹性悬挂参数时能够有效抑制车体的弹性振动, 并提高车体的垂向弯曲频率。采用三维刚柔耦合动力学模型仿真结果表明:车辆运行速度越高弹性悬挂的优点越明显, 车下设备横向偏载主要影响车体的横向振动特性, 纵向偏载主要影响车体的垂向振动特性;当车下设备的悬挂频率接近车体的垂向弯曲频率时能够降低车体的整体振动水平, 当车下设备的悬挂频率低于车体的垂向弯曲频率时, 提高车下设备弹性悬挂系统的阻尼能够在一定程度上抑制车体的弹性振动。

Influence of equipment under car on carbody vibration

In order to consider the elastic vibration of carbody, the vertical coupling vibration model of carbody and equipment was established, the influence of rigid suspension and flexible suspension on the amplitude-frequency characteristic of carbody was studied, in which carbody was modeled as an Euler-Bernoulli beam. The 3D rigid-flexible coupling dynamics model of high-speed EMU was set up based on the modal superposition method and considering carbody elastic vibration and equipment, the influence of equipment's suspension types, partial loads and suspension parameters on carbody vibration was andyzed. The numerical analysis result of Euler-Bernoulli beam model shows that reasonable elastic suspension design based on the principle of dynamic vibration absorber can effectively suppress the elastic vibration of carbody and improve the vertical bend frequency of carbody. The simulation result of 3D rigid-flexible coupling dynamics model shows that the higher the speed is, the more obvious the advantage of elastic suspension is, equipment's lateral partial load affects the lateral riding index of carbody, and the longitudinal partial load mainly affects the vertical riding index. When the flexible suspension frequency of equipment is close to carbody bend frequency, the minimum vibration of carbody occurs. But as the suspension frequency of equipment is less than carbody bend frequency, rising damping can suppress carbody vibration to some extent.