为研究多重调谐质量阻尼器(Multiple Tuned Mass Damper,MTMD)抑制桥梁单阶涡振的性能,建立桥梁结构-MTMD系统竖弯涡振广义单自由度动力方程,以某大跨度悬索桥为背景进行MTMD减振控制效果和参数优化分析.采用数值方法求解动力方程,获得系统在简谐涡激力下达到稳态谐振时结构的动力放大系数和MTMD对结构的附加模态阻尼比,并与单一频率调谐质量阻尼器(Single Tuned Mass Damper,STMD)的减振控制效果进行对比,然后以附加模态阻尼比为 目标对MTMD进行参数优化.结果表明:MTMD比最优参数STMD拥有更宽的控制频带和更好的减振效果,经优化后的MTMD减振性能优于最优参数STMD.实际应用MTMD时,应选择较大广义质量、5～7种频率规格,并根据二者找到无量纲频率范围和各TMD阻尼比的惟一最优取值.
Vertical Vortex-Induced Vibration Control Effect of MTMDs in Suspension Bridge and Parameter Optimization
This study investigates the damping effect of multiple tuned mass dampers(MTMDs)on vortex-induced vibrations(VIVs)of a single mode.A generalized single-degree-of-freedom dynamic equation to calculate vertical VIVs of the bridge-MTMDs system is established,and an existing long-span suspension bridge is used as a case to analyze the vibration damping effect of MTMDs and carry out parameter optimization.Numerical methods are employed to solve the dynamic equation to obtain the dynamic magnification factor of the bridge and the additional modal damping ratio contributed by MTMDs,when the system reaches the stable harmonic state under harmonic excitations.Afterwards,the vibration damping effect of the MTMDs is compared with that of the single tuned mass dampers(STMDs),and the parameters of MTMDs are optimized taking the additional modal damping ratio as the target.The results demonstrate that MTMDs own wider control bands and better vibration damping effect compared to STMDs with optimal parameters,indicating that the optimized MTMDs are superior to the STMDs with optimal parameters.It is recommended to select the MTMDs with greater general mass and with 5 to 7 frequency specifications,and use these data to find the unique optimal parameters of dimensionless frequency range and damping ratio of each TMD.
suspension bridgevertical vortex-induced vibrationmultiple tuned mass damperparametric optimizationdynamic magnification factoradditional modal damping ratiovibration control
万方数据
维普
