Influence of the random dynamic parameters of the human body on the dynamic characteristics of the coupled system of structure–crowd

Agu, E.; Kasperski, Michael

doi:10.1016/j.jsv.2010.06.029

Cited by 30 publications

(12 citation statements)

References 9 publications

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“…It can, however, be explained by an increased damping, i.e., due to the changes in the dynamic properties of the coupled human-structure system in comparison to those of the empty structure. However, accounting for the involved timevariant pacing rates allows to quantify the remaining discrepancy that is due to these human-structure interaction (HSI) effects 10,[15][16][17] . In this way, the methodology presented here provides essential input for the verification of the human-induced loads and quantification of HSI-effects.…”

Section: Representative Resultsmentioning

confidence: 99%

Simulation of Human-induced Vibrations Based on the Characterized In-field Pedestrian Behavior

Nimmen

Lombaert

Roeck

et al. 2016

JoVE

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For slender and lightweight structures, vibration serviceability is a matter of growing concern, often constituting the critical design requirement. With designs governed by the dynamic performance under human-induced loads, a strong demand exists for the verification and refinement of currently available load models. The present contribution uses a 3D inertial motion tracking technique for the characterization of the infield pedestrian behavior. The technique is first tested in laboratory experiments with simultaneous registration of the corresponding ground reaction forces. The experiments include walking persons as well as rhythmical human activities such as jumping and bobbing. It is shown that the registered motion allows for the identification of the time variant pacing rate of the activity. Together with the weight of the person and the application of generalized force models available in literature, the identified time-variant pacing rate allows to characterize the humaninduced loads. In addition, time synchronization among the wireless motion trackers allows identifying the synchronization rate among the participants. Subsequently, the technique is used on a real footbridge where both the motion of the persons and the induced structural vibrations are registered. It is shown how the characterized in-field pedestrian behavior can be applied to simulate the induced structural response. It is demonstrated that the in situ identified pacing rate and synchronization rate constitute an essential input for the simulation and verification of the human-induced loads. The main potential applications of the proposed methodology are the estimation of human-structure interaction phenomena and the development of suitable models for the correlation among pedestrians in real traffic conditions. Video LinkThe video component of this article can be found at

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Section: Representative Resultsmentioning

confidence: 99%

Simulation of Human-induced Vibrations Based on the Characterized In-field Pedestrian Behavior

Nimmen

Lombaert

Roeck

et al. 2016

JoVE

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“…Additionally, Wei and Griffin [1] found that seated passive people had a natural frequency of about 5 Hz with 45 % damping ratio; Dougill [3] suggested the bobbing body unit had a natural frequency of about 2.3 Hz with 25 % critical damping ratio. It is reported by Kasperski [2] recently that the induced damping of walking person exceeds that of a passive person and the damping value depends on the walking frequency. At this point of view, it is reasonable that the damping ratio of human body in walking is larger than the damping ratio of passive person in standing position.…”

Section: Discussionmentioning

confidence: 96%

“…Griffin [1] suggested six models to represent standing person as either a single degree-of-freedom (DOF) system or two DOFs system. Kasperski [2] proposed a probabilistic model for standing person. The internal biological forces were not included in these models.…”

Section: Introductionmentioning

confidence: 99%

Identification of Stiffness, Damping and Biological Force of SMD Model for Human Walking

Lou

Zhang

Chen

2015

Conference Proceedings of the Society for Experimental Mechanics Series

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This paper proposes an iterative identification approach to extract the stiffness, damping and coefficients of biological force of a spring-mass-damper (SMD) model for human beings in walking. Gait experiment records from 73 test subjects were used for the identification. The three-dimensional motion capture technology was adopted in the walking tests. Thirty-nine reflective markers were attached to each test subject during the test and the trajectories of each marker were monitored by motion capture system. The displacement, velocity and acceleration of center-of-mass of a subject in each test case were then obtained by the system. Assume that the biological force can be expressed by Fourier series, the parameters, including stiffness and damping of SMD model and coefficients of biological force, are identified by the following two steps.Step 1, initial guesses of damping ratio and natural frequency of SMD are introduced into the equation of motion to identify the coefficients of the first several orders of Fourier series and a new stiffness parameter.Step 2, acceleration resonance assumption is adopted to determine a new damping ratio parameter. Replace the conjectured/identified values in the previous step with the new values and repeat the above two steps until presumed convergence criteria is satisfied. The identified mean value of damping ratio and natural frequency of SMD slightly increase with the increase of walking frequency. The identified damping ratios are found larger than published values for people in standing posture. IntroductionThe vibration serviceability problem induced by occupant activities such as walking, jumping and running is a major concern or even a dominant design issue for long-span floors. Modern structural floor systems are prone to human-induced vibration because structures have become lighter and more slender with the use of high-strength lightweight materials. When the frequency of crowd is at or close to harmonics of natural frequency of the structure, the resonance response may cause discomfort to occupants or even structural damage. Therefore, vibration serviceability problems can't be ignored at the floor's design stage. Among several issues regarding vibration serviceability assessment, the human-structure-interaction (HSI) is a new one that addresses the influence of occupants on the dynamic properties of the system and the structural responses. Researchers have proposed some models to consider the influence of human-structure-interaction on the prediction of structural responses to human activities. Griffin [1] suggested six models to represent standing person as either a single degree-of-freedom (DOF) system or two DOFs system. Kasperski [2] proposed a probabilistic model for standing person. The internal biological forces were not included in these models. As for the person in bobbing, a simple and classical structural dynamic model has been used by Dougill [3], which represents the human body as a spring-mass-damper (SMD) model with an internal pair of biolo...

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“…The properties of the human body found in biomechanics literature may be available for structural engineering applications. It is important to note that, a wide array of values for vertical parameter model representations of passive humans were reviewed (Agu, Kasperski 2011), including the dynamic characteristics of sitting (Wei, Griffin 1998) and standing (Matsumoto, Griffin 2003). Few scientific papers have been published which address the biodynamic properties of the human body when exposed to whole-body vibration (WBV) (Fairley, Griffin 1990;Holmlund, Lundstrom 1998;Mansfield, Lundstrom 1999;Matsumoto, Griffin 2003, 2011Wei, Griffin 1998), most of them focused on single human at vertical vibration on experimental apparatus (e.g.…”

Section: Description Of the Passive Crowd-tdg Interaction Modeling Frmentioning

confidence: 99%

“…And for civil engineering, published literatures have demonstrated beyond any doubt that human on structures act as dynamic spring-mass-damper systems and the presence of human occupants can change the dynamic behaviour of structures considerably (Sachse et al 2003). This effect has already been ongoing from 1987s (Foschi, Gupta 1987) for floor system to 2011s for permanent grandstands (Agu, Kasperski 2011) given a literature review about human-structure dynamic interaction, and a slender structure (Busca et al 2014) or steel stair (Cappellini et al 2016). Another research studies regarding the analysis of dynamic response of permanent stadia structures, often subject to widely varying interpretations and many uncertainties were reviewed (Yao et al 2006) and a flexible test rig was developed for exploring crowd-structure interactions (Harrison et al 2006(Harrison et al , 2008.…”

Section: Introductionmentioning

confidence: 99%

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

Yuan

Fan

et al. 2018

Journal of Civil Engineering and Management

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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.

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Influence of the random dynamic parameters of the human body on the dynamic characteristics of the coupled system of structure–crowd

Cited by 30 publications

References 9 publications

Simulation of Human-induced Vibrations Based on the Characterized In-field Pedestrian Behavior

Simulation of Human-induced Vibrations Based on the Characterized In-field Pedestrian Behavior

Identification of Stiffness, Damping and Biological Force of SMD Model for Human Walking

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

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