Seismic failure modes and seismic behavior analysis of rocking truss-BRB-steel frame systems

The seismic failure mode of seismic design of building structures is the failure of full beam hinges. In reality, it is difficult to foresee the full beam hinge failure mode of the structure due to uncertainties. Owing to large ductility, Buckling-Restrained Braces (BRBs) can dissipate the energy impacted on structures subject to earthquakes. In view of this feature, a rocking truss-BRB-steel frame system is proposed in this study. The main failure modes of the structure were identified by the pushover analysis and its failure path was analyzed. Based on the time history analysis for cases of earthquakes with mild, moderate and severe intensities, peak story drifts and seismic performance of a conventional steel frame structure, a rocking truss-steel frame system and a rocking truss-BRB-steel frame system were compared and analyzed. The results showed that the rocking truss-BRB-steel frame system played an important role in the structural energy dissipation, the optimal control of the failure modes, and the reduction of the residual deformation of the structures. The lateral deformation of the rocking truss-BRB-steel frame system was more uniform than that of the traditional steel frame structure and the energy consumption of the whole-parts-structure was stronger.