@article{ref1,
title="Bistable gaits and wobbling induced by pedestrian-bridge interactions",
journal="Chaos, solitons and fractals",
year="2016",
author="Belykh, Igor V. and Jeter, Russell and Belykh, Vladimir N.",
volume="26",
number="11",
pages="e116314-e116314",
abstract="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.<p /> <p>Language: en</p>",
language="en",
issn="0960-0779",
doi="10.1063/1.4967725",
url="http://dx.doi.org/10.1063/1.4967725"
}