Optimum distribution of viscous fluid dampers in structural systems

This paper demonstrates the usefulness of viscous fluid dampers (VFDs) with toggle bracing mechanism in controlling the vibration of three-storey frame model by comparing their performance with buildings having only diagonally placed VFDs. It has been shown from the studies carried out that provision of VFDs with toggle bracing mechanism at ground floor level would act like vibration dampers. This results in controlling the vibration levels at higher floor levels. The optimum distribution of VFDs with toggle bracing mechanism in three-storey moment resistant steel framed buildings has been studied. For this building frame the placement of VFDs with toggle brace mechanism along the height of the building is found to be effective. The results suggest that the bracing system proposed in this paper can be effectively used in retrofitting of existing buildings and in performance based design of new ones for earthquake loads.