斜拉桥拉索磁流变阻尼器减振技术研究

采用数值仿真和现场试验对磁流变阻尼器的减振性能进行了研究。数值仿真计算评估了磁流变阻尼器安装高度、外部激励、阻尼器输入电压等参数对拉索系统模态阻尼比的影响 ,结果表明磁流变阻尼器具有良好的阻尼可调特性 ,调节阻尼器的输入电压可以获得拉索系统的最佳模态阻尼比 ;现场试验表明 ,安装该阻尼器后 ,拉索系统的模态阻尼比提高 3～ 6倍 ,并存在一优化电压 ,在该电压下模态阻尼比达到最大 ;实际风雨振时的现场观测结果显示 ,磁流变阻尼器具有很好的减振效果 ;拉索磁流变阻尼器减振技术已在岳阳洞庭湖大桥全桥实施 ,解决了该桥的风雨振问题

Study of mitigating cables vibration on the cable-stayed bridges using magnetorheological (MR) dampers

To investigate the performance of mitigating cables vibration of MR dampers,numerical simulations and field tests are conducted in this paper.Relations of some parameters, such as location of attachment,excitation to cables and voltages input to dampers versus modal damping ratios of cable system are acquired.Simulation results indicate that the variable damping can be obtained by adjusting voltages input to MR dampers. Field tests show that modal damping ratios of cable system will increasing 3~6 times after attaching MR dampers to cable and there exists an optimal voltage,in which voltage maximum modal damping ratio can be acquired. Excellent effect of mitigating cable vibration of MR damper has been verified with the monitoring results of an actual wind rain induced vibration. Mitigating cable vibration using MR dampers has been implemented successfully on Yueyang Dongting Lake Bridge.