MTMD减振技术在大跨度悬挑连廊设计中的应用

Application of MTMD vibration reduction technology in design of a large-span cantilever corridor

针对最大悬挑长度为35.2m大跨度悬挑连廊在人致激励下的舒适度问题,采用有限元分析软件SAP2000建立结构三维分析模型,计算多种人致激励工况下结构减振前后的加速度响应,对比了调谐质量阻尼器(TMD)和多重调谐质量阻尼器(MTMD)减振方案的减振效果。分析结果表明:连廊在人致激励作用下产生的最大加速度超过舒适度限值,利用TMD可有效减小结构振动,改善舒适度性能。但单频TMD控制频带较窄,只对特定振动频率的减振效果明显。为改善其鲁棒性,拓宽有效频带宽度,最终采用具有分布频率的MTMD减振方案,在保证经济性最优的前提下,对多种频率激励荷载均得到了显著的减振效果,使连廊满足舒适度要求。

Aiming at the comfort of the large-span cantilevered corridor with a maximum overhang length of 35.2m under human-induced excitation,a three-dimensional structural analysis model was established using the finite element analysis software SAP2000 to calculate the acceleration response of the structure before and after vibration reduction under various human-induced excitation conditions,and the vibration reduction effects of tuned mass damper(TMD)and multiple tuned mass damper(MTMD)vibration reduction schemes were compared.The analysis results show that the maximum acceleration of the corridor under human-induced excitation exceeds the comfort limit,and adopting TMD can effectively reduce the structural vibration and improve the comfort performance.However,the single-frequency TMD control frequency band is narrow,and the damping effect is only obvious for the specific vibration frequency.In order to improve its robustness and broaden the effective frequency band width,the MTMD vibration reduction scheme with distributed frequency was finally adopted.On the premise of ensuring the optimal economic performance,significant vibration reduction effects are obtained for various frequency excitation loads,so that the corridor meets the comfort requirements.