MECHANICAL ANALYSIS OF REINFORCED BEAM-CFST COLUMN JOINT UNDER SEISMIC LOADING

The concrete-filled steel tubular structure is widely used in practice because it shows perfect seismic performances such as good ductility and strong ability to resist collapse under seismic loadings. The numerically computed hysteresis curves and sketch curves of concrete-filled steel tubular (CFST) column to reinforced concrete beam joint under different axial load levels were compared with experimental results in this paper to verify the accuracy of the finite element model and to reveal the anti-seismic properties of the joint. By analyzing the behavior of CFST joint under typical axial load level, the development of cracks and deformations is studied, and the ultimate state and the failure mode are determined. In addition, the variation of the rebar strain, the concrete constraint force and the shear force in the joint core are obtained. The effect of the axial load level on the failure mode is determined by comparing the stresses in the core concrete and the shear fore in the joint core under different axial load levels at the ultimate state.