ABSTRACT
The CBF frame to be tested features an experimental configuration using pinned connections at the bottom of the brace members. This allows both compression and tension braces to be tested in the same plane, thus avoiding any stiffness eccentricities. For the sake of brevity, both gusset configurations to be tested are shown in Figure 1. During testing, one gusset type will be tested at a time. Gusset plate design details are currently being finalised. Gusset Plate A will form a semi-rigid connection hence stiffening the frame considerably compared to Gusset Plate B which possess characteristics more related to a pinned connection. The frame
1 INTRODUCTION
The increase in popularity of concentrically braced frames (CBF) can be attributed to a combination of their desirable stiffness for reducing inter-storey drifts and the unexpected, poor performance of moment resisting frames as evidenced during the 1994 Northridge earthquake. Extensive experimental research into their seismic performance has been undertaken in recent times. Early cyclic tests of brace members carried out by Black et al. (1980) and Jain et al. (1980) showed that global slenderness has a significant influence on the overall hysteretic behaviour of brace members. Thus, this remains a fundamental consideration when estimating the ductility capacity of brace members. Tang and Goel (1989) later developed a criterion to predict the fracture life of bracing members and found that it is highly sensitive to section slenderness, particularly in compression flanges susceptible to local buckling.
