Fire Performance of Concrete Filled Steel Tube Frame Restrained Steel Beams

In order to propose the method for the fire resistance design of steel beams,a finite element( FE) model was proposed to simulate the fire performance of steel beams with shell element. The FE model was then used to study the failure mode,the deformation and internal force redistribution of the steel beams in fire. At the same time,the fire performance of the isolated steel beams was compared with that of the steel beams in frame structures. The results show that the boundary conditions have much influence on the failure mode of the steel beams; the axial compression force of the isolated steel beams is bigger than that of the steel beams in the frame structures.