Experimental research of seismic performance of buckling-restrained braced frame with ductile connections

Abstract

The connection joints of Buckling-Restrained Braced Frames are critical to the performance of structures. The maximum ductility and cumulative ductility of Buckling-Restrained Braces are sufficiently large, and the ductility of beam-column connection of steel frame should be matched with that of the BRB component, then the structure would exhibit good global performance. The pseudo-static test of a 1/3 scale 2-story 1-span buckling-restrained braced frame (BRBF) system consisting of the reduced beam section (RBS) connections were conducted. The performance of BRBF with reduced beam section (RBS) connections was analyzed, and the deformation capacity of ductile connection was studied. The RBS sections on the beam ends effectively protect the beam-column connections of BRBF, and better deformation capacity can be achieved to provide large ductility up to 4.75. For BRBFs using new connection, the maximum roof drifts before the failure were governed by the rotational capacity of the beam-column connections and the stability performance of the BRBs. The global ductility of structures is highly relevant to the local ductility of beam-column connections and BRBs. The yielding sequence of structural components followed as BRBs, ductile connections and structural members, which is the reasonable plastic development of the structure for seismic design. The test BRBF underwent a big amount of fully-reversed hysteretic curves without strength or stiffness degradation during the significant drift demands imposed by the subsequent quasi-static cyclic test, which possessed good global ductility and energy dissipation capacity.