Static behavior of planar intersecting CFST connection in diagrid structure

Intersecting connection plays an important role in the new diagrid structural system for high-rise buildings. To investigate the static behavior of the intersecting connection of concrete-filled steel tubular (CFST) columns, a typical reduced-scale planner connection specimen is tested under monotonic axial compression. The failure modes, force mechanism and bearing capacity of intersecting CFST connections are analyzed further in the follow-up numerical simulation, considering influences of intersecting angle, elliptical plate and ring plate. Test and simulation results prove that, intersecting connection can develop fully plastic deformation and provide sufficient bearing capacity. Parametric analysis indicates that bearing capacity of planar intersecting CFST connection mainly depends on intersecting angle and thickness of elliptical plate, while the ring plate affects that little. Capacity estimation method for planar intersecting CFST connection is proposed basing on the capacity of the critical section which is located near intersecting center for a distance of steel tube radius, and the design suggestions is provided in the end of this paper.