Seismic performance of eccentrically braced frames

Abstract

The main objective of this research is to assess the seismic performance of Eccentrically Braced Frames of different configurations. Modelled Eccentrically Braced Frames subjected to both linear and nonlinear analysis in SAP 2000. The linear analysis gives an insight to mode shapes and mass participation ratios. The nonlinear analysis includes the pushover analysis, which provides information about the collapse mechanisms and performance points. This study also extended to compare the performance of Eccentrically braced frames with the performance of Special Moment Resisting Frames that helps to understand the structural efficiency of both systems. This study concludes that all selected configurations of Eccentrically braced frames undergo small roof displacement that is well below the target drift whereas SMRF frames will show large displacement. 2D braced EBFs shows a better post yielding behaviour and is more ductile compared to other frame systems. Shear links in the EBF frames increase the stiffness of the frame which in turn results in high base shear demand. Post yielding behaviour of EBF frames can be improved by proper detailing of beam-column joints and link connections which confirms that performance of EBF frames is superior to SMRF frames in seismic areas.