Cyclic Testing of Steel Chevron Braces with Vertically Slotted Beam Connection

Authors

Department of Civil Engineering, University of British Columbia, Vancouver, Canada

Abstract

Experimental tests were performed to study the seismic behavior and performance of
modified steel chevron braced frame systems, which incorporate a vertical slotted connection
(VSC) detail between the top of the braces and the floor beam above. The VSC detail is
intended to prevent vertical load transfer to the beam and limit brace forces to the
compressive resistance of the members. Full-scale quasi-static cyclic tests were performed on
two specimens with hollow tube braces, with one specimen having the braces filled with
concrete. Both frames exhibited stable, predictable behavior under cyclic loading. The VSC
detail provided free vertical movement of the brace assembly during both tests. However, its
flexibility created a moderate reduction in the overall lateral stiffness of the frame. The
concrete-filled tube specimen sustained higher peak loads, demonstrated greater residual
strength and dissipated more energy than the hollow tube specimen due to the partial
inhibition of local buckling by the concrete core. It was found that the VSC chevron braced
frame system is a suitable concept for use in buildings in high-risk seismic zones.

Keywords