Pedestrian traffic induced lateral vibration including the effect of TMD

Abstract

This study explores the dynamic behavior of beam induced by bipedal pedestrian traffic and corresponding vibration reducing method by tuned mass damper. Each pedestrian from motion crowd simplifies as a bipedal robot comprised of a lump mass and two massless spring-damping legs. In addition, the tuned mass dampers are installed on the bottom of structure to relieving the vibration of structure. The interactions among pedestrians, tuned mass dampers and structure are considered to establish a governing equation. Research indicates that both the tuned mass damper and pedestrian evidently alter the structural properties of the structure by affecting its frequency and damping capacity. The structure tends to be gently flexible at a lower frequency as pedestrian walk across its surface, but the corresponding damping capacity of the structure is improved. The tuned mass damper always improves both the vibration response and dynamic properties of structure. However, its self-dynamic characteristics of the tuned mass damper tend to deteriorate. The tuned mass damper relieves effectively the lateral vibration in a slender structure than the rigid structure. The change in the mass ratio of tuned mass damper to structure affects significantly the dynamic behaviors of structure. In addition, the layouts of the tuned mass dampers on structure also have remarkable influences on the behaviors. The results of this study provide potential pathways for understanding the vibratory mechanisms of slender structures such as footbridges, grandstands, or stations under crowd excitations.