Bistable gaits and wobbling induced by pedestrian-bridge interactions
Bistable gaits and wobbling induced by pedestrian-bridge interactions
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DOI：
10.1063/1.4967725
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发表时间：
2016-11-01
期刊：
影响因子：
2.9
通讯作者：
Belykh, Vladimir N.
中科院分区：
文献类型：
--
作者：
Belykh, Igor V.;Jeter, Russell;Belykh, Vladimir N.
世界各地的几座现代人行桥在人群装载活动中经历了很大的横向振动。大幅值桥梁抖动的开始通常被归因于人群的同步；尽管它在开始抖动中的作用受到了挑战。为了研究单个行人对整体人群动力学的贡献，我们使用了一个生物力学启发的倒立摆人体平衡模型，并分析了它与一座活泼的桥梁的双向相互作用。我们首先推导出在没有桥梁运动的情况下行人横向步态频率的解析估计。然后，通过理论和数值计算，我们证明了行人与桥梁的相互作用可以诱导双稳态的横向步态，使得步态之间的切换可以引发大幅度的摆动。我们还分析了步频和行人质量在两种摆动之间的滞回转换中的作用。我们的结果支持了这样一种说法，即行人不同阶段行走的整体脚力会导致显著的桥梁振动。由AIP出版公司出版。
Several modern footbridges around the world have experienced large lateral vibrations during crowd loading events. The onset of large-amplitude bridge wobbling has generally been attributed to crowd synchrony; although, its role in the initiation of wobbling has been challenged. To study the contribution of a single pedestrian into overall, possibly unsynchronized, crowd dynamics, we use a bio-mechanically inspired inverted pendulum model of human balance and analyze its bi-directional interaction with a lively bridge. We first derive analytical estimates on the frequency of pedestrian's lateral gait in the absence of bridge motion. Then, through theory and numerics, we demonstrate that pedestrian-bridge interactions can induce bistable lateral gaits such that switching between the gaits can initiate large-amplitude wobbling. We also analyze the role of stride frequency and the pedestrian's mass in hysteretic transitions between the two types of wobbling. Our results support a claim that the overall foot force of pedestrians walking out of phase can cause significant bridge vibrations. Published by AIP Publishing.