COLLAPSE ANALYSIS OF CONCRETE FILLED STEEL TUBULAR COLUMN - STEEL BEAM PLANAR FRAMES

A finite element analysis (FEA) model of CFST (concrete filled steel tube) column-steel beam planar frames is presented in this paper. The collapse criteria of this kind of planar frame is discussed. Alternate path method is used to simulate the collapse of the composite frame. The distribution of the deformation and internal force of the frames are analyzed. The results show that the deformation of the left frame structure mainly concentrates at the beam ends. The composite frame according to design codes can satisfy the requirement of collapse when the failure of joints is ignored. However, the forces increase significantly in the joints next to the lost column, which become one of key parts in the design considering collapse.