Human-Structure Interaction Based On The Bipedal Walking Model

Human-structure dynamic interaction (HSI) is an important but relatively new topic in designing slender structures occupied and dynamically excited by humans. Human-structure synchronization in both the vertical direction and lateral direction during walking was often regarded as the human-structure dynamic interaction by many researchers. If the amplitude of vibration of structure exceeds a critical value, the pedestrians are affected by the motion and tend to adjust their walking frequency and phase, synchronizing with the motion of the structure. Various mathematical models of human-induced dynamic walking loads have been proposed to include this interaction in the dynamic analysis of the structure. In all of these models, the crowd was only an imposed load rather than a dynamical system. This ignores the possibility of interaction that can occur due to the ’mechanical’ properties of the human body and the structure. The different influencing parameters associated with the walking force, such as the stiffness, damping, length and the angle of attack of human leg, do not have contributions in these models. Therefore, the mechanism of human-structure dynamic structure can not been studied using those models.The principal aim of this paper is to study the dynamic response of a structure under a pedestrian by considering the effect of interaction between the human and structure. The main contents of this paper are as follows:(1) Firslty, the equations governing human-structure static interaction are derived. The frequency and damping of the system are obtained by using the state-space method. Based on the above, the influences of ratio of mass, frequency, damp coefficients of human to structure and human location on the dynamic characteristics of systems are studied. Comparing the numerical simulations with the experimental results made by British scholars shows that the dynamic model is correct and reasonable.(2) The human-structure dynamic interaction problem based on bipedal walking model and damped compliant legs is presented in this paper. A time-variant damper is modeled at a given walking speed. A control force is applied by the pedestrian to compensate for energy dissipated with the system damping in walking and to regulate the walking performance of the pedestrian. The effects of stiffness, damping of the leg and the landing angle of attack are investigated in the numerical studies. Finally, an experiment that a pedestrian walks on a simply supported plate was carried out to illustrate the performance of the proposed interaction model.(3) A three-dimensional bipedal walking model with compliant legs is presented in this paper. A time-variant damper is modeled at a given walking speed, and the feedback control for both the forward and lateral movements is included to regulate the walking performance of the pedestrian. The leg stiffness and attack angle effects are investigated in the numerical studies.(4) The dynamic response of a footbridge under a pedestrian by considering the effect of interaction between human and structure is studied based on three-dimensional bipedal walking model. The pedestrian system and structural system are integrated together for studying the lateral vibration of structure from such interaction. The classical finite element method is combined with the moving finite element to represent the pedestrian motion with all effects. The equations of motion of the human-structure system will be presented, in which a control force in feedback manner together with the lateral balance control law, are provided by the pedestrian to compensate for energy dissipation in walking and to regulate the walking performance of the pedestrian.