Seismic Analysis of Eccentrically Braced High-rise Steel Frames

The eccentrically braced steel frame is a good moment-resisting system,widely used in high-rise structures,but its seismic performance in severe earthquake needs some in-depth study.This paper,based on an eccentrically braced high-rise apartment,with software SAP2000,has calculated the stiffness and stress distributions,the vibration modes and load-displacement curves etc.in severe earthquake,and it compared the dynamic/ aseismatic characteristics of eccentrically and centrally braced frames by elastic and elasto-plastic time history analyses.The analyses reveal that,the lateral stiffness of eccentrically braced highrise frames satisfies the requirements of lateral resistance;the eccentrically braced frames behaves better than centrally braced frames as the higher lateral stiffness and resistance in plastic stage in severe earthquake.