MD and SMD model parameters of pedestrians for vertical human-structure interaction

Light and slender structures are prone to vibration serviceability problems due to pedestrians. The interaction between pedestrians and structures is one of the challenging issues in accurately predicting structural vibrations. Based on the test data from a low-frequency footbridge under pedestrians' loading, mass-damper (MD) model and spring-mass-damper (SMD) model are used to model pedestrians on the footbridge and their model parameters are extracted. First, the frequency response functions (FRF) of the empty footbridge and occupied footbridge are obtained from the test data. Second, MD model and SMD model are used to model pedestrians and to build coupled models of the pedestrians and the footbridge. Third, MD and SMD model parameters of a single pedestrian are extracted by fitting the theoretical FRF for the measured FRF. Results show that a single pedestrian contributed 40% of his/her real mass and 1400 kg/s to the footbridge in our case. The SMD model of a single pedestrian has a natural frequency of 1.9 Hz and a damping ratio of 30%. To the best of the authors' knowledge, no SMD parameters of pedestrians have been reported elsewhere. However, a comparison between SMD parameters obtained in our paper and those in the literature from static humans with different gestures is done, justifying the application of SMD model to pedestrians. In the end, numerical simulation is done to unveil the limitation of MD model and SMD model is recommended as a proper model of pedestrians for application in human-structure interaction (HSI). © 2016, Nanjing Univ. of Aeronautics an Astronautics. All right reserved.