Full scale tests of all-steel buckling restrained braces

Buckling-restrained braces (BRBs) are widely used seismic response-controlling members with excellent energy dissipation capacity without buckling at design deformation. However, the property of all-steel BRBs with cruciform cross section encased in a square steel tube remains insufficiently studied. In this paper, the properties of this kind of BRBs, which were used in two office buildings in Beijing, were examined by full-scale test. First, initial design was done according to the client's requirement. Then, two full-scale specimens were tested under uniaxial quasi-static cyclic loading. The test results indicate that there should be no welding in yielding portion of the core. Finally, the full-scale subassemblage test was done with an improved BRB and gusset plates installed in a frame. The result shows that the brace exhibited high energy dissipation capacity and stable hysteretic characteristic. According to the results from above tests, some important issues are summarized to provide advices for practical applications.