Finite element method analysis of hybrid structural frames with reinforced concrete columns and steel beams

Two frame specimens with reinforced concrete columns and steel beams, which had different beam-column joint detailing, were analyzed using the nonlinear three-dimensional finite element method (FEM). One specimen had through-beam-type beam-column joints with face bearing plates, and the failure mode was beam yielding. The other specimen had through-beam-type beam-column joints with cover plates, and the failure mode was joint shear failure. Analysis of the, latter was conducted before testing to predict the behavior of the specimen. FEM analysis that took into consideration the interaction between the reinforcement and concrete and that between the steel and concrete simulated the behavior of the frame specimen,well. The failure process and shear resisting mechanisms of differently shaped beam-column joints (interior, exterior, interior top, and corner) were-understood by analytical results,of the stress-strain relationship among concrete elements, shear force of the beam-column joints, the contribution of shear resisting elements, and deformation components, which were not obtained in the experiment.