SEISMIC RESPONSE ANALYSIS OF ECCENTRICALLY BRACED STEEL FRAME

Eccentrically braced steel frame is a lateral load-resisting system that is popularly applied in high earthquake hazard area, because of its high elastic stiffness to meet the high-rise steel structure needs of drift requirement. This paper focuses on studying response and performance of eccentrically braced steel frame structure under horizontal seismic load. Based on ANSYS, a 7-floors eccentrically braced steel frame structure is set up to model its seismic response. Several parameters, such as length of energydissipation beams segment, ratio of floor height to span length, number of storey and vertical load, are discussed how they affect the seismic performance of eccentrically braced steel frame. The results show that some factors, like joints types, length of energy-dissipation beams segment, structural height, ratio of structural height and its span, vertical load level, etc., have a great effect on seismic response of eccentrically braced steel frame structure. This study has already proved that the energy-dissipation beams segment bears great moment and shear force during the structural seismic response, the energydissipation beams segment will be yielded and damaged in lower structure, but for high-rise structure, the beam will not dissipate the energy.