Cyclic tests of all-steel web-restrained buckling-restrained brace subassemblages

•Web-restrained braces (WRBs) utilize standard steel bar stock used for metal buildings.•Four WRB frame subassemblages were subjected to AISC 341–10 test protocol for BRBs.•Three different sizes of steel core plates were examined.•All specimens exhibited stable and repeatable behavior up to 2% story drift.•The 12.7-mm thick core plate specimens endured additional cycles at 1.5% story drift.

In this study, cyclic tests of a buckling-restrained brace (BRB) subassemblage with an all-steel web-restrained brace (WRB) were conducted to investigate hysteretic behavior under combined axial and rotational demands. Four full-scale WRB frame subassemblages were subjected to the quasi-static displacement protocol used for BRB qualification described in the AISC 341–10 Seismic Provisions for Steel Buildings. Three different sizes of steel core plates were examined. One specimen used a nominal 7.9-mm thick by 152-mm wide plate, two WRB specimens used a nominal 12.7-mm thick by 152-mm wide plate, and one specimen used a nominal 12.7-mm thick by 229-mm wide plate. All specimens successfully completed the cyclic testing up to 2% story drift without experiencing brace instability, brace end connection failure, or rupture. Specimens with a 12.7-mm thick core plate survived additional cycles at 1.5% story drift before rupture. The test results also showed that the maximum compression forces were less than 1.3 times the maximum tension forces for each cycle corresponding to a deformation greater than the yield displacement, demonstrating that compression overstrength of the WRB was comparable with typical BRBs.