Cyclic Flexural Testing of Concentrically Braced Frame Beam-Column Connections

Abstract

This research investigates the cyclic flexural behavior and performance of concentrically braced frame beam-column connections in the context of evaluating the reserve lateral load-resisting capacity in concentrically braced frames. Eight beam-column connections with gusset plates, employing double angle and end plate details, were studied using full-scale experiments to determine their flexural strength, stiffness, and ductility. In this paper, the effects of connection parameters, such as end plate thickness, angle thickness, bolt configuration, weld type and size, and supplementary seat angle, are evaluated. The global connection behavior and performance are quantified using normalized moment versus story drift data. In comparison to a baseline double angle detail, all connection variations increased the strength and stiffness. The end plate variations resulted in larger increases in strength, but drift capacity was limited by bolt fracture. The double angle variations increased the strength by smaller margins, but strength loss occurred more gradually, and larger drifts were sustained. The double angle connection configuration with a supplemental seat angle is shown to provide the best balance of strength and deformation capacity.