A finite element analysis（FEA）model was developed for sequentially coupled heat transfer and mechanical analysis of concrete filled steel tube（CFST）column to reinforced concrete（RC）beam joints under fire

which was validated by the experimental results available in the literature.The FEA model was then used to investigate the influence of material parameters

geometric parameters

load parameters and the constrained stiffness at beam ends on the fire resistance of CFST column to RC beam joints

and particularly the effect of axial and rotational constrained stiffness at beam ends on the moment versus rotation angle relationship

rotational stiffness and distribution of sectional inner forces of CFST column to RC beam joints in fire.The results show that CFST column to RC beam joints have two kinds of failure model:column failure and beam-slab failure.The constraint at beam ends has little influence on the fire resistance of CFST column to RC beam joints;however

the axial constraint has a significant impact on the moment versus rotation angle relationship

rotational stiffness and distribution of sectional inner forces of the composite joints in fire.