Vibration control of seismic forces using viscous dampers and buckling restrained braces in irregular composite buildings

Abstract

This study addresses the effectiveness of buckling restrained braces (BRBs) and viscous dampers (VDs) in dissipating seismic energy and increasing the seismic performance of irregular composite buildings during earthquake events. The seismic response of steel-concrete composite moment resisting frames of 15 stories with concrete filled steel tubes (CFST) as columns and composite beams was examined with and without seismic protection devices by employing ETABS software using the response spectrum method as per IS 1893:2016 for seismic zone V. Regular and irregular plans characterised the structures. The plan irregular buildings include C and L-shaped buildings. The BRBs and VDs were installed on all the buildings in two configurations: corner bays and centre bays throughout the height. The results showed BRBs and VDs excellent energy dissipation capabilities. VDs contributions were 5%-8% more than BRBs and, therefore, more efficient. Centre bays placement of VDs was most efficient for regular buildings reducing time-period by 60%, maximum story displacement by 57%, base shear by 37%, and maximum interstory drift ratio by 70%. Corner bays placement of VDs was most efficient for C and L-shaped buildings reducing time-period by 55%-60%, maximum story displacement by 63%-65%, base shear by 30% and 13%, and maximum interstory drift ratio by 78%-80%, respectively, making viscous dampers an excellent choice for midrise composite buildings.