Seismic Performance Analysis of CFST Composite Column-reinforced Concrete Beam Joints

In order to further study the seismic performance of CFST composite column-reinforced concrete （RC） beam joints, we take a CFST column of a subway station as the prototype. Based on the equivalent stiffness method, the stiffness equivalent calculation of the composite column and the steel tube column was carried out. Its bending stiffness was obtained through pushover, and the mechanical properties of CFST columns and CFST composite columns were explored. The CFST column-RC beam joint model and the CFST composite column-RC beam joint model were established by using ABAQUS, and the accuracy of the node models were verified through existing literature experiments. The hysteretic characteristics, skeleton curve, stiffness degradation, and ductility ratio of the two joints were compared. The calculation results show that under the action of small axial compression ratios, the energy dissipation capacity, hysteresis performance, and ultimate load of CFST column joints are better than those of CFST composite column joints. With the increase of the axial compression ratio, the difference in energy consumption between the two joints is small. When the axial compression ratio is 0.9, the seismic performance of the CFST composite column joint is better than that of the CFST column joint. Replacing the CFST column-RC beam joint with the CFST composite column-RC beam joint will not cause a significant decrease in the structural seismic performance.