Preliminary seismic analysis of fabricated steel frame systems with pin beam-column connections and buckling restrained braces

This study aims to propose an improved fabricated high-rise steel frame system with buckling restrained braces (BRBs) and pin beam-column connections, which is applicable to seismic areas. In this system, damages to the main structural members resulted from earthquake ground motions can be prevented by BRBs which are capable of resisting all the lateral seismic loads, whilst the other structural members are mainly responsible to carry the gravity loads. Having explicit load-carrying characteristics, this system is thought to have a competitive advantage of rapid construction. In this study, a 3D finite element model of a specific fin-plate connection, a typical type of pin beam-column connections, is built and its rotational stiffness is evaluated. Subsequently, a high-rise steel frame model with both BRBs and the fin-plate connections are established. The earthquakeresistant performances of the model under different levels of seismic excitation are analyzed using the nonlinear dynamic time-history method. Numerical results indicate that the proposed system performs elastically under frequent earthquakes, whereas under severe earthquakes the main structural components are well within their capacities. Furthermore, the BRBs show significant energy dissipation capacity under severe earthquakes