Frame and Brace Action Forces on Steel Corner Gusset Plate Connections in Buckling-Restrained Braced Frames

Abstract

This work presents test and finite element analysis results for a steel buckling-restrained braced frame (BRBF). The objectives are to evaluate the forces of frame and brace actions on the corner gusset plate and to develop a method that considers both actions in design. The BRBF test frame exhibited excellent performance up to a drift of 2% with a maximum axial strain of 1.7% in the buckling-restrained brace. Without free-edge stiffeners, the corner gusset plate buckled at a significantly lower strength than that predicted by the American Institute of Steel Construction (AISC) specifications ( AISC 2005a ). By idealizing the corner gusset plate as a strut, a strut model can be used to determine the forces resulting from frame action, which are on the same order as the brace forces. Considering the stress distributions and force components from the frame and brace actions, the maximum stresses in the gusset tips are used as an additional design parameter for sizing gusset connections.