Simplified theoretical treatment of lateral structural properties under crowd excitation
Yun Dong1 , Yan An Gao2 , Ye Zhu3 , Peng Zhang4
1, 2, 3, 4Faculty of Architecture and Civil Engineering, Huaiyin Institute of Technology, 223001, China
1, 2, 3, 4Jiangsu Urban and Rural Residential Structure Assembly Technical Engineering Laboratory, 223001, China
1, 2Corresponding authors
Mathematical Models in Engineering, Vol. 4, Issue 4, 2018, p. 191-200.
Received 27 August 2018; accepted 6 September 2018; published 31 December 2018
Walking crowd-induced lateral vibrations on slender structures have attracted considerable attention. The improper vibration of a structure adversely affects human comfort. To explore the effects of crowds on lateral structural properties, a pedestrian from a crowd is simulated by a walking bipedal robot. A simplified theory for structural vibration is proposed based on the assumptions of uniform distribution and synchronized walking of pedestrians. This theory can be used to describe the effect of the change in crowd size on lateral structural damping and the frequency of the structure. The method can estimate the variations in structural properties in the case of a certain crowd for engineering design. The results show that the increase in crowd size results in decrease in structural natural frequency in the lateral direction, but increases structural damping. The influence of the crowd on structural properties agrees well with the non-simplified model. Change in walking frequency has little influence on the structural properties. However, the continuous increase in crowd size on structure top causes a non-convergent amplification of dynamic response under a resonant walking excitation. This research provides a quantitative assessment on the effect of crowd size on the change in structural properties for structural design or serviceability evaluation.
Keywords: lateral vibration, dynamic properties, crowd excitation.
This research is supported by the Major Projects of Natural Science Research in Jiangsu Colleges and Universities (17KJA560001), National Natural Science Foundation of China (51808247), Natural Science Foundation of University in Jiangsu Province (18KJB560003), the Natural Science Foundation of Jiangsu Province (BK20160426), the Science and Technology planning project of Jiangsu Province (BY2016061-29), the Natural Science Foundation for Colleges and Universities in Jiangsu Province (17KJB130003) and the Project with Science and Technology of Huai’an City (HAG201606). The help from Ding Zhou is also acknowledged.
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