Two Simplified Models for Human-Structure Vertical Interaction

Based on a mass-spring-damper（MSD）model and a mass-spring-damper-rigid mass（MMSD）model, which are two kinds of pedestrian simplified models, the equations of vertical dynamic interaction pertaining to a simplified human-structure were deduced by the regularization structure modal function. Using the dynamic equation with non-proportional damping characteristics, the state-space method was used to solve the instantaneous frequency and damping ratio of the system equations; the difference between the two coupled dynamic equations and the change regularity of frequency and damping ratio of the structure under walking load were discussed, and the difference in the structural acceleration response in a human-structure coupled state was analysed. The results show that the structural damping ratio between the two kinds of equations is significantly different; however, the instantaneous frequency of the structure is only slightly distinct, considering the vertical interaction between a human and a structure. The instantaneous damping ratio peak increases by an average of 31.67%, and the instantaneous frequency reduces by an average of 0.29%. Human-structure vertical interaction must be considered in response to human-induced structural vibration analysis. The difference in structural dynamic responses between the MSD and MMSD models is very small, and the difference in the root mean square acceleration is only 0.34%.