NCBF1: UW Non-Seismic Conetrically Braced Frame (NCBF) with Welded Continuous 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 continuous welded 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 = 27.0 > 13.8). Connection deficiencies included gusset plate yielding of the Whitmore section, gusset plate shear yielding, gusset plate-to-beam and gusset plate-to-shear tab weld fracture, brace net section rupture, brace block shear rupture, and gusset plate block shear rupture. AWS E70T-7 weld metal, which does not meet minimum toughness requirements for demand critical welds, was used except on the gusset plate-to-beam and shear tab-to-column welds, where notch-tough weld metal 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.