Nonlinear Finite-Element Analysis of the Seismic Behavior of RC Column–Steel Beam Connections with Shear Failure Mode

RC column–steel beam (RCS) systems, a novel type of hybrid structure, have been used widely in recent decades owing to their excellent seismic performance and simple fabrication process. However, due to the effects of variable strengthening configurations on force-transfer mechanisms, the mechanical behavior of RCS connections has not been fully understood by existing experimental studies. This paper proposes a reliable finite-element model of RCS connections and investigated the effects of different strengthening configurations and design parameters on the seismic performance and shear mechanism. A detailed three-dimensional finite-element model was developed and validated against previously obtained experimental results, including load–displacement relationships and cracking patterns. Parametric studies based on the validated model were conducted. The studies showed that the axial load ratio significantly affects the failure mode and ductility of the connection. The load-carrying capacity of the connection is enhanced significantly when the concrete strength is increased. Furthermore, additional yield capacity of steel plates and transverse reinforcements has limited effects on crack propagation and strain state when adequate resistance can be provided.