基于TMD的钢弹簧浮置板轨道结构改进研究

为提升钢弹簧浮置板轨道低频域制振性能,应用有限元方法建立地铁车辆-钢弹簧浮置板轨道耦合动力学模型,对带凸台的常规钢弹簧浮置板轨道进行结构改进设计。参考某地铁实际线路,基于TMD定点理论以及多自由度系统等价质量识别法,通过对无凸台钢弹簧浮置板轨道进行模态分析和谐响应分析,确定钢弹簧浮置板凸台下减振元件的最优刚度、最优阻尼;然后基于车辆-钢弹簧浮置板轨道耦合动力学模型,研究列车动荷载作用下钢弹簧浮置板轨道改进前后低频域制振效果。结果表明:改进后的钢弹簧浮置板轨道能够有效地抑制轨道板固有频率附近频段的低频振动;合理的TMD参数匹配能够有效地控制列车动荷载下钢弹簧浮置板基频范围内的低频振动及对应频段钢弹簧支反力向周围基础的传递。

Research on Steel Spring Floating Slab Track Improvement Based on TMD

In order to improve the performance of steel spring floating slab track( SSFSTs) of lowfrequency vibration control,a coupled dynamic model of metro vehicle-steel spring floating slab track is established with finite element method to improve the structure design of the common steel spring floating slab track with convex block. With reference to an actual metro line,the optimal stiffness and damping coefficient of the damping element under the convex block of the steel spring floating slab track are determined based on the modal analysis and the harmonic response analysis of the steel spring floating slab track, the turned mass damper( TMD) fixed-point theory, and the identification method of equivalent mass for multi-degree-of-freedom systems. Further,the effectiveness of low-frequency vibration control of the SSFSTs subject to dynamic train loads before and after revision is evaluated based on the vehicle-track coupled dynamic model. The results show that the revised SSFST can effectively absorb low-frequency vibration energies of the SSFST adjacent to natural frequencies; the reasonable TMD parameters can effectively suppress lowfrequency vibration of the SSFST under dynamictrain load and reduce the transmission of steel-spring supporting counter forces to nearby foundations.