Performance evaluation of a multistorey steel frame with viscous fluid dampers in lower toggle configuration

Abstract

The performance evaluation of a 20-Storey steel moment resisting frame [1] incorporated with viscous fluid dampers in lower toggle configuration under earthquake loads was carried out using SAP 2000 software. The time history analysis was carried out with El Centro, Kobe, Northridge and S_Monica earthquake time histories. The peak ground acceleration (PGAs) for the model building is assumed as 0.35g. The Time history analysis for bare frame and the frame with dampers placed in six different configurations were done to find their optimum placing to perform better under earthquake forces. The absolute acceleration (a), displacements (d), inter-storey drifts (dr) produced in all six different model frames with different configurations of lower toggle mechanisms due to earthquake forces are found out. The optimum damper configuration was arrived from the analytical results. The peak average response reduction values for the optimum Lower toggle configuration of viscous dampers in the model frame are found out as 69.0, 59.1 and 68.6 for absolute acceleration, maximum displacements and inter story drifts respectively.