NCBF3-1: UW Non-Seismic Concentrically Braced Frame (NCBF) with Bolted Split Shear Tab and Non-Ductile HSS Brace

This specimen consisted of a single-bay one-story concentrically braced frame with single-diagonal bracing. The frame was intended to be representative of existing non-seismic concentrically braced frames (NCBFs) with split bolted shear tab connections at brace-beam-column intersections. The braces and connections were deficient with respect to the 2010 AISC Seismic Provisions. The HSS brace did not meet the compactness limit for highly ductile members required for SCBFs (b/t = 22.8 > 13.2). Connection deficiencies included beam-to-shear tab bolt bearing and shear, gusset plate-to-shear tab bolt shear, gusset plate-to-beam weld fracture (evaluated using the balanced design procedure), brace net section rupture, and brace block shear rupture. AWS E71-T11 weld metal, which does not meet minimum toughness requirements for demand critical welds, was used. The specimen was loaded quasistatically through a load beam bolted to the north beam using a reversed cyclic increasing amplitude loading protocol. Traditional physical sensors and optical sensors were installed on the specimen. Portions of the specimen were whitewashed to detect yielding.