Using MSD model to simulate human-structure interaction during walking

Increasing vibration serviceability problems of modern pedestrian structures have drawn researchers' attention to detailed modelling and assessment of walking-induced vibration on floors and footbridges. Stochastic nature of human walking and unknown mechanisms of their interaction with the structure and surrounding environment, make it difficult to simulate. Ignoring these complexities has rendered the current design methods to a rough approximation of reality which often leads to considerable over or under-estimalion of the structural response yielding unreliable assessment of vibration performance. Some aspects of human-structure interaction (HSI), such as synchronization, have been studied extensively, mostly in the lateral direction. But, despite of its much bigger significance, effects of walking pedestrians on dynamic properties of structures in the vertical direction are mostly ignored. This is mainly due to the lack of credible HSI experimental data in the vertical direction as well as models capable of simulating the interactions between the two dynamic systems. To address this gap, this paper tries to adapt a classic single degree of freedom mass-spring-damper (MSD) model of human body to illustrate the effects of walking pedestrians on dynamic properties of structures. Parametric studies were carried out to analyse effects of the human model dynamic properties on coupled system response. This MSD model can be seen as the basic building block of realistic human body models which are currently being developed to address both biomechanical specifics and HSI effects on structures occupied and excited by walking human.