Fire Performance Analysis And Design Of Concrete-filled Steel Tubular Column With Encased Profiled Steel

The concrete filled steel tubular(CFST) column with encased profiled steel combine the advantages of CFST columns and steel reinforced concrete(SRC) columns,so it exhibits a good prospect for practical engineering.In recent years,the researchers from all over the world performed on the basic mechanical performances research of this kind of composite members at ambient temperature,but there are scarce research results on the fire resistance of this kind of columns.This paper carried out the aspects of work as follows:(1) A numerical model of the CFST column with encased profiled steel was built using ABAQUS based on the reasonable thermal parameters and the material properties of concrete and steel.The finite element method(FEM) model were verified by a large number of fire tests of CFST columns and SRC columns and concrete-filled steel tube reinforced concrete(CFSTRC) columns,respectively.The numerical simulation analysis on the temperature distribution and fire endurance were compared with experimental results.Meanwhile,the FEM model also were verified by a series of experiment of the CFST column with encased profiled steel under axial compression,eccentric compression and bending at ambient temperture.The numerical ultimate bearing capacity was agree well with the experimental result.(2) The fire resistance limit of CFST column with encasd profiled steel was calculated,in order to CFST column with encasd ―十‖profiled steel as an example,analyze the stress and strain,interaction forces between the components and the load distribution subject to ISO834 was also carried out.(3) The fire endurance of CFST column with encasd profiled steel were calculated subject to non-uniform fires by a finite element mode(FEM),analyze the development of stress and strain for the kind of column,finally,the parameters analysis was carried out.This paper collects some tests of full-range fire,numerical simulation calculated agree well with the experimental.Axial load versus displacement curves were calculated and strain distribution were analyzed when exposure to full-range fire,parametric studies of members were also calculated,and the change of stress and strain in the whole process fire were discussed.