Seismic Performance of Buckling Restrained Braced Steel Frames Considering BRB Connection

Abstract Previous studies of BRBF showed that there are two main requirements to reach the desired mechanical behaviour of buckling restrained braced frames (BRBF) under seismic loadings. This behaviour could be represented by sufficient plastic deformation and ductility capability of core plate member. 1) The first requirement is to prevent overall buckling of BRB; and 2) the second requirement is to prevent out-of-plane buckling of gusset plates. This study focuses on the second main requirement through presenting finite element analysis results of several proposed gusset plates and two joint sections for connecting core plate member with gusset plate. Further, study the impact of proposed gusset plates and joint sections on behaviour of steel frames. The pushover analysis that performed in this study is followed the method that discussed in AISC-2010 Seismic Provision manual. Therefore, the proposed connection of buckling restrained braced steel frame required to sustain cyclic loadings start with elastic drift up to two times of design drift. The analysis results showed that the proposed connections sufficiently sustain all the axial force from BRB without out-of-plane buckling occurs or losing the stable hysteretic response of the BRB, finding that the equal dimensions of gusset plate vertical length and horizontal length has much better effect on frame.