方钢管混凝土柱-钢梁节点在往复荷载下的力学性能

finite element method (FEM) study is conducted herein to simulate the cyclic behaviour of steel beam to concrete filled steel tubular (CFST) column joints under a constant axial load and a cyclically increasing lateral load to simulate forces. The finite element program ABAQUS was used for the analysis. A plastic damage model for concrete and elasto-plastic model for steel were used to simulate the damage and degradation of the materials. Eight specimens of steel beam to square concrete-filled steel tubular (CFST) joints using an external ring were tested to assess the hysteretic behaviour under combined constant axial load and cyclical lateral load. The axial load level of the CFST column, width of connection stiffening ring were considered as influential experimental parameters to the seismic behaviour of the specimens. The lateral load (P) versus lateral deformation (Δ) hysteretic curves showed no obvious strength deterioration and stiffness degradation. It can be concluded that the joints exhibited good seismic performance. It was also found that the axial load level had an influential effect on both the strength and seismic behaviour of the joints. The lateral ultimate strength of the joints reduced and the displacement ductility and the energy dissipation capacity decreased with an increased axial load level. Furthermore, the failure mode of the joints changed from a plastic hinge in the beam end to fracture in the ring zone. The eight specimens tested were analysed using a FEM model. The results obtained from the FEM model showed reasonable agreement with the experimental results.