PRELIMINARY RESEARCH ON FIRE RESISTANCE OF CONCRETE-FILLED STEEL TUBULAR COLUMNS TO COMPOSTE BEAM FRAME

摘要

This paper presents a finite element analysis(FEA) model of concrete-filled steel tubular(CFST) columns to steel beam frame with RC slab to investigate the fire performance and provide reasonable fire resistance design method based on ABAQUS.The reasonable thermal and material models were chosed in the FEA model.Due to lacking of experimental datas about the fire behavior of composite frame,the FEA model results were verified by the fire performance of CFST columns to composite beam joint and CFST columns to RC beam frame experiments,respectively.Typical failure modes and displacement of beam and column versus fire time relationships were studied to calculate the fire resistance of the frame.The results show that the fire duration time of composite frame is increased significantly with the increased of the thickness of fire protection and decreased the fire load ratio of columns.The fire resistance of composite frame columns is larger than the single columns due to the absorption of heat and the constraint function of the reinforced concrete slab.