The Research On The Anti-seismic Performance Of A Rectangle Section Buckling Restrained Brace

Because the concentrically braced frame can offer older resisting stiffness to structure, widely used in the seismic area. But in Northridge earthquake(1994) and Hyogo-ken earthquake(1995), a large amount of destruction appeared in the building of this kind of system. Studies have suggested, because of brace buckling early, the strength of sturucture is dropped. In order to improve the buckling performance of brace, make in earthquake occurrence, no buckling of brace will take place, as to traditional concentrically braced frame put forward a new system can avoid brace buckling, called buckling restrained braced frame. This system is a large amount of adopt already in Japen and U.S.A., demonstrates good anti-seismic performance.In the present, the study about buckling restrained brace is focused on the brace in steel tube concrete. In this paper, makes the theory analyze to a rectangle section buckling restrained brace which restrained system is composed of steel paltes and steel tubes, derives of equation of stiffness about this brace and all requirements that every parts should be met. At the same time, finite element analysis is also performed. The analysis results indicate, this kind of buckling restrained brace having good dissipation energy ability, and improve the difficult in connection and quality of concrete casting.On this basis, the further research of anti-seismic of buckling restrained braced frame is performed. Derive additional damping and influence of buckling restrained brace to column axis strength. Example proved, as to concentrically braced frame, buckling restrained braced frame has better anti-seismic performance. Meanwhile, the study of impact on structural anti-seismic of buckling restrained brace is also performed.