磁浮工程道岔梁的TLMD减振技术研究

Study of TLMD Vibration Mitigation Technique for Switch Beams in Maglev Project

为了解磁浮道岔梁的车桥耦合振动机理并进行振动控制,以长沙中低速磁浮工程道岔梁为工程背景,对磁浮工程道岔梁的TLMD减振技术进行研究。首先通过对磁浮道岔梁在磁浮列车激励下的振动响应测试,分析加速度的时程曲线和频率特征,研究其振动机理,确定道岔梁的受控频率;然后采取频率分布式的多重TLMD阻尼减振方案,并利用基于多目标满意度优化方法,对各TLMD进行参数优化;最后在实桥安装TLMD阻尼器后进行实桥测试,对安装阻尼器前、后道岔梁的振动响应进行对比。研究结果表明:磁浮工程道岔梁和磁浮列车的悬浮调整力形成了共振,振动响应剧烈,由于其振动频率明确,可以采用调谐式阻尼器进行控制;采用优化的TLMD阻尼器方案的理论减振效果明显;通过实测对比,安装TLMD阻尼器后,道岔梁的振动基本被抑制,满足日常行车的要求。

To examine the mechanism of vehicle-bridge coupling vibration of the maglev switch beam and conduct vibration control, the switch beams in the Changsha medium-low speed maglev train project were taken as the subject of study of the TLMD （tuned liquid mass damper） vibration mitigation techniques used to the switch beams in maglev project.First, the vibration responses of the maglev switch beams under the excitation of maglev train were tested, to analyze the characteristics of the time-history curve of acceleration and frequencies, study the vibration mechanism and determine the controlled frequencies of the switch beams.Then, the vibration damping scheme of using multiple TLMDs of frequency distribution type were used and the optimization method based on multi-target satisfaction was adopted, with the intension of optimizing the parameters of TLMD.After the LTMDs were installed on a real bridge, the vibration responses of the switch beams before and after the installation of the dampers were tested and compared.The results of the study indicate that resonant vibration was triggered by the switch beams in the maglev project and the maglev adjusting force and the vibration responses were dramatic.Due to the fact that the vibration frequencies were clear, it was possible to take the tuned dampers to control.The theoretical vibration mitigation effect of the optimized TLMD scheme was distinct.By field testing comparison, it was concluded that the vibration of the switch beams were basically thwarted after the TLMDs were installed, which met the routine train-riding demands.