Three-dimensional exact solution Concrete Filled Steel Column under pressure composite to thermal load

As main load-bearing member, Concreted Filled Steel Column (CFSC) has been widely used in buildings and bridge structures. Research on bearing capacity of CFSC, especially under temperature load, was carried out mainly on the basis of experiments. In this paper, inverse method of elastic theory is adopted to introduce Airy stress function for study on CFSC under axial pressure and temperature load. And the analytical expressions for stress of steel tube and concrete, interaction forces between them, and internal temperature of the column are obtained. Based on the abovementioned expressions, it is concluded that temperature, radial stress, and normal stress in the same plane of CFSC are functions of the radius. And the internal temperature can only be affected by thermal conductivity coefficient of steel tube and concrete; the radial stress and normal stress are affected not only by the stiffness, but also by the thermal conductivity coefficient of steel and concrete.