Abstract：The mechanical characteristics of five steel-plate assembled buckling restrained braces (BRBs) were compared. Different design parameters, such as the constraint ratio, the loading schedules, and the unbounded materials, were considered in the low cyclic reversed loading tests. The experimental results indicate that the unbounded materials can be used to reduce the friction force between the external constraint units and the core units. The BRB with unbounded materials demonstrates a full hysteresis loop, stable energy-dissipated capacity and substantial anti-fatigue properties. The steel-plate assembled BRB with unbounded materials exhibits a bilinear curve of the equivalent viscous damping ratio with its axial deformation. The BRB with the constraint ratio less than 1 is unstable with overall buckling. The loading schedules show little influence on the hysteretic performance of the BRB. Since the BRB should yield before the main structures, and early failure of BRBs due to inadequate plastic deformation capacity should be avoided, μmax is suggested larger than 13 and CPD should be no less than 1200 in the engineering practice.
