杠杆式调谐质量阻尼器对双吊索尾流致振的减振优化

Optimal design of lever-type tuned mass dampers for control of wake-induced vibrations of coupled twin-cable hangers

围绕双索股长吊索整体风致振动及其减振控制问题,开展了节段模型风洞试验和基于杠杆式调谐质量阻尼器的减振设计和试验研究。通过节段模型测振风洞试验,研究了悬索桥双圆柱索股的整体风致振动特性及其不稳定区间;推导了考虑自激力作用的吊索整体振动杠杆式调谐质量阻尼器最优设计参数,并分析了各参数对减振效果的影响;根据最优参数设计了杠杆式调谐质量阻尼器,进行了双吊索整体尾流致振的控制实验,验证了各参数对减振效果的影响。结果表明:双吊索在6°⁃10°风攻角区间发生了大幅风致振动;与基于简谐力外荷载作用的TMD优化相比,按基于自激力作用的运动方程进行TMD参数优化,能显著减少抑制尾流致振的TMD质量比;杠杆式调谐质量阻尼器能有效提高双吊索整体风致振动起振风速,阻尼器参数偏离会降低减振效果,其中频率偏差影响最为明显。

The hangers of suspension bridges at each hanger point are composed of 2 or 4 cable bundles,and the close proximity of cable bundles in each hanger may induce complex wind-induced vibrations.In this study,wind-induced vibrations of twin cable bun⁃dles with various distance of gap are investigated by wind tunnel tests and its vibration control is treated with the lever-type tuned mass dampers(LT-TMD).The wind-induced instability of coupled parallel twin hanger ropes are investigated by elastically-sup⁃ported section model wind tunnel tests.The optimal parameters of the LT-TMD to control the wind-induced instability are derived based on the self-exciting force model,and the effect of the dynamic parameters of the LT-TMD on control is discussed.The wind tunnel tests of coupled parallel hanger ropes installed a LT-TMD are carried out.The results of this study indicate that:1)the cou⁃ple parallel hanger ropes tend to suffer from larger amplitude wind-induced vibrations as the wind attack range is in the range from 6°to 10°;2)compared with the optimal design of LT-TMD based on the harmonic external exciting model,the optimal design based on the self-exciting force model can significantly reduce the mass of the LT-TMD;3)LT-TMD can effectively improve the on-set wind speed of wind-induced instability,the deviation of dynamic parameters for the LT-TMD will reduce the vibration re⁃duction effect,especially for the frequency deviation.