高架轨道箱梁C型弹簧动力吸振器减振研究

Vibration Reduction of C-type Spring Dynamic Absorbers for Elevated Track Box Girder

为有效控制高架轨道箱梁的振动,首先设计并建立轨道-箱梁、动力吸振器物理模型,通过理论计算和数值仿真,分析动力吸振器的移频特性,对其参数、尺寸及安装位置进行优化设计;然后对轨道-箱梁结构进行模态分析,通过振型贡献率确定结构的受控模态;最后基于列车-轨道-桥梁耦合模型,探讨列车荷载作用下动力吸振器对轨道-箱梁结构的减振效果。结果表明:动力吸振器可以通过C型弹簧的变形来改变弹簧刚度,进而改变自身固有频率以对不同频率的振动进行控制;根据振型贡献率,轨道-箱梁结构以2阶模态为控制模态进行减振设计;简谐荷载及移动荷载作用下,动力吸振器可以在宽频范围内有效抑制轨道-箱梁结构的振动,最大可减低3.2 dB。

In order to effectively control the vibration of elevated track box girder,the physical model of track-box girder and dynamic vibration absorber was designed and established.Through theoretical calculation and numerical simulation,the frequency shift characteristics of the dynamic vibration absorber were analyzed,and its parameters,size and installation position were optimized.Then,the modal analysis of the track-box girder structure was carried out,and the controlled mode of the structure was determined by the modal contribution rate.Finally,based on the train-track-bridge coupling model,the vibration reduction effect of the dynamic vibration absorber on the track-box girder structure under train load was discussed.The results show that the dynamic vibration absorber can change the spring stiffness through the deformation of the C-type spring,and then change its natural frequency to control the vibration of different frequencies.According to the contribution rate of vibration mode,the track-box girder structure was designed with the second-order mode as the control mode.Under the action of harmonic load and moving load,the dynamic vibration absorber can effectively suppress the vibration of the track-box girder structure in a wide frequency range,with a maximum vibration reduction of 3.2 dB.