抄録
An analytical method for thermal elasto-plastic-creep three dimensional deformation behavior of steel wide-flange columns at elevated temperatures is presented. This is a combined-nonlinear finite element procedure based on the finite displacement theory of the thin-walled open cross section, and uses the mechanical model of structural steel at high temperature, which was proposed by authors in the past. The calculation of moment-rotation relationships of steel columns at constant temperatures are performed in order to get the information for maximum strength of steel columns at high temperature. Also, the calculation of deformation behavior of steel columns at increasing temperature under constant external loads are performed in order to investigate the effect of creep strain on the deformation and the collapse temperature of steel columns at elevated temperature. As a result of investigating examples, it is shown that the reduction of maximum strength of bi-axial bending columns at 300〜400℃ is larger than that of columns bent about strong axis only.
