Effects of human-structure interaction on the dynamic properties of a grandstand

Abstract

In structural engineering, human occupants have traditionally been considered as external loads with noconsideration being made for changes they can produce in the dynamic properties of the structure. Hence, the current interest in proposing dynamic models for human occupants that interact with structural models and account forchanges in the dynamic properties of the structure. This article presents the characterization of the effects that humanoccupants have on the fundamental natural frequency and corresponding equivalent viscous damping ratio of astructure that was built such that its fundamental natural frequency is similar to that of the grandstand of the PascualGuerrero Stadium, in Cali, Colombia. Forced vibration tests were conducted on the grandstand with both dead loadsand human occupants in different positions and occupation densities. Results show that for the case of the structurewith human occupants, the fundamental natural frequency and corresponding damping ratio can vary up to 35% and27% respectively, with respect to those of the structure with equivalent dead loads.