Crowd-induced random vibration of footbridge and vibration control using multiple tuned mass dampers
Crowd-induced random vibration of footbridge and vibration control using multiple tuned mass dampers
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DOI：
10.1016/j.jsv.2010.04.013
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发表时间：
2010-09-13
影响因子：
4.7
通讯作者：
Chen, Yu
中科院分区：
文献类型：
--
作者：
Li, Quan;Fan, Jiansheng;Chen, Yu
本文研究了人群随机行走引起的人行天桥的振动特性，并提出了多调谐质量阻尼器（MTMD）在抑制人群引起的振动中的应用。开发了步行引起力的垂直分量的单脚力模型，避免了连续步行力的相位角难以接近。在单脚力模型的基础上，考虑人行天桥最恶劣的振动状态，建立了人群-人行天桥随机振动模型，将行人建模为以平均车头时距为特征的人群流。在此随机振动模型中，开发了解析公式来计算任意跨度布局的人行桥任意位置的加速度功率谱密度。当人行桥固有频率落在人群激励的频率带宽内时，可以观察到共振效应。为了抑制过大的加速度，影响人类正常行走的舒适度，采用MTMD系统来改善人行天桥的动态特性。根据随机振动模型，引入基于人行桥最大均方根加速度最小化的优化程序来确定MTMD系统的最优设计参数。数值分析表明，所提出的随机优化程序设计的MTMD比传统的MTMD设计方法更能有效地降低人群人行桥共振时的动态响应，并且适当的频率间隔放大将有效减少MTMD的失谐效应。 (C) 2010 Elsevier Ltd. 保留所有权利。
This paper investigates vibration characteristics of footbridge induced by crowd random walking, and presents the application of multiple tuned mass dampers (MTMD) in suppressing crowd-induced vibration. A single foot force model for the vertical component of walking-induced force is developed, avoiding the phase angle inaccessibility of the continuous walking force. Based on the single foot force model, the crowd-footbridge random vibration model, in which pedestrians are modeled as a crowd flow characterized with the average time headway, is developed to consider the worst vibration state of footbridge. In this random vibration model, an analytic formulation is developed to calculate the acceleration power spectral density in arbitrary position of footbridge with arbitrary span layout. Resonant effect is observed as the footbridge natural frequencies fall within the frequency bandwidth of crowd excitation. To suppress the excessive acceleration for human normal walking comfort, a MTMD system is used to improve the footbridge dynamic characteristics. According to the random vibration model, an optimization procedure, based on the minimization of maximum root-mean-square (rms) acceleration of footbridge, is introduced to determine the optimal design parameters of MTMD system. Numerical analysis shows that the proposed MTMD designed by random optimization procedure, is more effective than traditional MTMD design methodology in reducing dynamic response during crowd-footbridge resonance, and that the proper frequency spacing enlargement will effectively reduce the off-tuning effect of MTMD. (C) 2010 Elsevier Ltd. All rights reserved.