Research on seismic behavior of CFST column-H-beam fully assembly joint

At present, the studies of the joint of concrete-filled steel tubular (CFST) columns-H-shaped steel beams mainly focus on its traditional cast-in-place construction methods. It lacks studies on the realization of prefabricated CFST column-H-shaped steel beam joint prefabricated assembly connection. The traditional cast-in-place construction method is hard to ensure the pouring quality of concrete and is not conducive to the development of prefabricated buildings in this connection form. Therefore, a joint that realized the full assembly of prefabricated CFST columns-H-shaped steel beams was proposed in this paper, the seismic performance of which was inves-tigated by using low-cycle repeated experiments and simulations. The test indicated that the thickness of the end plate in the core area impacted immensely the failure mode and bearing capacity of the fully assembled joint. However, the energy dissipation capacity and plastic deformation capacity were less affected. Meanwhile, the simulation indicated that the mechanical performance of the core area of the joint can be improved by an appropriate thickness of the steel tubular column. Nevertheless, the excessive local deformation of the end plate caused a decrease in the energy dissipation capacity of the joint. The thin thickness of the end plate caused the end plate at the flange to be subjected to excessive deformation and the core area column not to be fully utilized, resulting in a significant decrease in the bearing capacity and stiffness of the joint. Finally, the initial rotational stiffness calculation model of the assembled joint was established and the stiffness matching relationship be-tween the joint components was determined.

Automated summary

Currently, research on the joint between concrete-filled steel tubular (CFST) columns and H-shaped steel beams mainly focuses on traditional cast-in-place construction methods, lacking studies on prefabricated assembly connections. This study proposes a fully assembled joint for prefabricated CFST column-H-shaped steel beam connection, and investigates its seismic performance through experiments and simulations. The results show that the thickness of the end plate greatly impacts the failure mode and bearing capacity of the joint, while energy dissipation capacity and plastic deformation capacity are less affected. Simulation indicates that an appropriate thickness of the steel tubular column can improve the mechanical performance of the joint's core area, but excessive local deformation of the end plate decreases energy dissipation capacity. Thin end plate thickness leads to excessive deformation at the flange and underutilization of the core area column, resulting in a significant decrease in bearing capacity and stiffness of the joint.