Seismic Performance of Different Types of Connections Between Steel Bracing and RC Frames

Abstract

In this paper, the seismic performance of three different types of connections between steel braces and concrete frames is assessed through numerical analyses. Two of the connection types are similar to the conventional diagonal steel brace–steel frame connections, while the third type is a new connection specifically designed for increased ductility. Results of previous experimental studies are first used to verify the accuracy of numerical models of the connections. The connections are then incorporated into brace–RC frame systems, and nonlinear cyclic analyses of the brace–frame assemblage are carried out. The response hysteresis loops of the frames are then used to evaluate such strength and performance parameters as capacity, stiffness, stiffness degradation, energy dissipation, equivalent damping ratio and ductility ratio for the frames. These parameters are then compared for the frames containing the three different types of connections. It is found that while the two conventional connections can perform effectively when the capacity and stiffness of the frame are of prime interest, the new connection enhances ductility and improves energy absorption capacity of the frame.