The Dynamic Parameters of Passive Human at Temporary Demountable Grandstands During Exposure to Lateral Vibration

Abstract

Modelling the interaction between crowds and temporary demountable grandstands with identifying the human dynamic properties are challenges for structure optimal design. In this paper, for investigating and understanding the human and structural lateral dynamic features. A demountable grandstand was tested to obtain its model parameters firstly. Then it is tested at amplitudes between 0.16 m/s2 to 1.54 m/s2 with 75 random waves through a shaking table when occupied by twenty persons. Afterword a simplified two-degree of freedom lumped dynamic model of the joint human-structure system is reinterpreted. Utilizing the state-space model, the passive crowd dynamic parameters are obtained, based on root mean square accumulation error analysis. Statistical analysis of the predictive results concludes that seated crowd model damping ratio is 0.5, and the probable natural frequency is 2.0 Hz with the model mass ratio 0.7. For standing crowd model, the probable natural frequency is 1.5 Hz with the model mass damping ratio 0.4, and the model mass ratio is 0.7. It may have ability to serve as a reference value that can be utilized in vibration safety and serviceability assessment of TDGs, to estimate realistically the vibration response on the occasions when crowd are seated or standing.

Dynamic Forces of Swaying Human and Responses of Temporary Demountable Grandstand Based on Experiment and Simulation

“…(3) It is an extreme case when all the persons swaying together; in fact, only a part of crowds have swaying movements in most cases, in particular, for rooters at sports or live concerts. So, the condition is that the 235 persons in the 8th row to 12th will sway and others are passive crowd and the frequency of passive human is 2.0 Hz and damping ratio is 0.3 which accords to the literature [37]. is model was calculated just only when the swaying frequency is 1.8 Hz.…”

Investigation of Dynamic Responses and Vibration Serviceability of Temporary Grandstands by a 3 DOF Interaction Model due to Swaying Motion

“…Parameters. According to the author's paper [20], there are three common approaches to determining vibration amplitude: peak, root-mean-square (RMS), and vibration dose value (VDV). VDV approach may be more suitable for assessing the structural vibration by dynamic curves especially the curve has distinct peaks that is different from RMS approach which depends too heavily on the duration of an event to act as an accurate gauge of response severity [4].…”

“…is paper follows with interest the latter key area issues for predicting the dynamic responses of temporary grandstand structure. e theory of interaction model usually considers that crowd and/or structure is mathematically assumed as a mass-spring-damper SDOF system [17][18][19][20], respectively. Other researchers such as Reynolds [21][22][23], Caprioli [24,25], Salyards [26], Cigada [27,28], Comer [29], Parkhouse [30], and Jones [31] monitored and analyzed the permanent grandstands using experiments.…”

“…What these reviews have highlighted is that vibrations induced by humans have vertical motions, and few researches analyzed the lateral vibration in the TDG. What is more, lateral vibration is more likely to be induced than vertical vibration in reality for TDG [14,20]. is remains an open problem in the area, and the aim here is to investigate the lateral vibration of TDG.…”