Experimental and numerical analyses of blind bolted moment-resisting composite joints to CFST columns with RC slab

In this paper, experimental and numerical analyses were conducted to investigate the structural properties and failure modes of the blind bolted flush or extended end plate joints between concrete-filled steel tubular (CFST) columns and composite beams. The experimental program and the main results of the tests were elaborated. Four full-scale subassemblages beam-tocolumn exterior joints to hot-rolled and cold-formed CFST columns were tested. The failure modes and moment-rotation relation curves of the joints were evaluated. The test results showed that all specimens exhibited favorable strength and stiffness, and larger deformation capacities. Meanwhile, finite element analysis (FEA) modeling of the specimens was built and analyzed. The results obtained from the FEA modeling were satisfactory agreement with the experimental tests results. Then, an extensive parametric study was conducted to investigate the influence of various parameters on the moment capacity and rotation stiffness of composite joints under positive or negative moment. The experimental studies and numerical analyses can improve the design of the typed joints to be used in moment-resisting composite frames.