Seismic Behavior of Assembly Joint with CFST Column and H-shaped Steel Beam

Existing concrete-filled steel tubular (CFST) structures are mostly based on cast-in-situ concrete construction technology. The beam-column joint emphasizes the horizontal connection, while the vertical connection of columns is mostly based on a steel tube connection instead of a precast CFST column connection; this is detrimental to the control of the concrete pouring quality and the full assembly of the structure. Thus, the investigation of an assembly joint that enables the full connection between the beam and CFST column is the key to the improvement of the construction quality and the promotion of the development of the assembled structure. This work proposes an assembly joint between an H-shaped steel beam and a CFST column, and the seismic behavior of the joint was investigated by low-cycle loading experiment. The finite element model of the joint was then established by the numerical analysis method. After verifying the rationality of the finite element model, the influences of both the endplate thickness and the bolt diameter on the energy dissipation performance of the joint were investigated via parametric analysis. The results reveal that with the increase of the endplate thickness and the bolt diameter within a certain range, both the bearing capacity and energy dissipation capacity of the joint will be improved. Moreover, the cooperative bearing mechanism of the column connector and concrete can be fully exerted. Thus, these conclusions indicate the feasibility of the use of the proposed assembly joint in practical engineering applications. Finally, the mechanical mechanism of the assembly joint was studied, and the calculation formula of the joint bending capacity was proposed.