行人移动荷载引起的桥梁结构振动是大跨桥梁设计的共性和热点问题,针对大跨悬索人行桥在行人移动荷载作用下的振动响应开展减振控制研究,采用频域分析法推导了桥梁-MTMD体系的频率响应方程,并据此对MT-MD系统的数量、频带宽、阻尼比等进行了参数优化分析,进而研究了最优参数条件下桥梁-MTMD体系在不同行人移动荷载模式下的振动响应与减振效果。研究结果表明桥梁振动响应随同步频人数的增多而逐渐增大,随桥梁振动频率与激励频率的接近而逐渐增大;优化的MTMD系统能够在较宽频率范围内对大跨悬索桥结构的振动反应进行可靠、稳定的控制,有效保证了大跨悬索桥在行人移动荷载作用下的安全性和舒适性。
Vibration responses of bridge structures in pedestrian moving loads have been a commonality and hot issues for footbridge design , especially for large-span bridges .Vibration control using MTMD for large-span suspension footbridges in pedestrian moving loads was focused in this study .The frequency-amplitude function of the bridge-MTMD system was derived based on the frequency-domain analysis meth-od.Parameter optimizations of the MTMD , such as number , frequency bandwidth and damping ratio , were also conducted according to the frequency-amplitude function .And then, the vibration responses and control effects of the bridge-MTMD system in different pedestrian moving loads were discussed in de-tail.The results show that the bridge responses increase gradually with increasing of the number of the same-rhythm pedestrians , and also with closing between the bridge and pedestrian frequencies .The opti-mized MTMD can ensure reliable and stable control for the vibration responses of the suspension bridge in wider frequency range .The safety and comfort of the large-span suspension footbridge in pedestrian mov-ing loads can be well guaranteed using the MTMD technology .