A finite element model（FEM） for calculating the temperature field and mechanical behavior of concrete-filled steel tube（CFST） plane frames under local fire is presented in this paper.Temperature distribution under different fire protection cover thickness is studied considering the influence of floor slab.Then

the deformation and failure mechanism

ultimate state

internal force state and the fire resistance of the CFST plane frames in fire is discussed by using the FEM.The results show that the temperature distribution mode of the heated beams is mainly controlled by the fire protection cover thickness

and the frame failure in fire is induced by the global buckling of the steel beams.