Based on a practical engineering of large span transfer structure
the model of 3-story reinforced concrete transfer structure with superimposed vierendeel truss is established.The nonlinear FEM software ABAQUS is used to analyse the deformation of the model
which is exposed to standard fire and coupling with vertical loads.Based on the simulation results of 9fire cases
the displacements of measured points and heating-up time curves are plotted.The numerical results show that on the basis of the deformations under vertical loads at normal temperature
the transfer structure models produce complicated additive deformations with the heating-up time increasing.As to the effects of 9fire cases
the fourth fire case has important effect on vertical deformation of the bottom joists
followed by the second fire case.With the heating-up time increasing
the vertical deformation is fast and not convergent.The symmetry of the deflection curves along transfer girder span is consistent with the symmetry of fire cases
and the deflection peak of transfer girder appears in the side of the room on fire in the unsymmetry fire cases.The cases of side span on fire are unfavorable.With the heating-up time increasing
the lateral displacements of two side columns of the model increase gradually in different fire cases.Because of the thermal expansion of the beam in burning floor
the lateral displacements outward of side columns in burning floors are significantly larger than other floors.