This paper aims to numerically investigate the response of steel columns in compression when exposed to elevated temperature. Numerical simulations using finite element computer program SAFIR have been carried out to study the behavior of axially loaded steel columns under uniform increasing temperature. Based on the numerical results it has been found that there is a direct correlation between the failure load at 400°C and the coefficient Ky,0 which can be used to calculated failure temperatures above 400°C. Two formulations for the buckling coefficient are proposed based on the hypothesis of an exponential shape function at 400°C. Good agreement is found between the analytical formulations and the F.E. results. Another formulation based on a logarithmic shape function is also studied and it is shown that it is in excellent agreement with the results from the F.E.A. Finally a new formula to calculate the failure load/ultimate temperature of axially loaded columns is presented.
2010 Structures Congress. Proceedings of the 2010 Structures Congress (Orlando, FL May 12-15, 2010) p. 3252-3261