Resistance of axially and eccentrically loaded steel column at high temperature: A simple expression

The study of the behaviour of steel structures at elevated temperature has become more and more important in structural design in recent years. Nevertheless, there are few design Code provisions and researcher expressions for predicting the steel column resistance on local buckling under fire conditions. In this paper a rather simple expression for predicting the resistance of steel column subjected to both axial and eccentrical load under high temperature is proposed. This expression considers the dependence of the steel column resistance on the relative slenderness at the collapse temperature. The steel column resistance values at high temperature obtained with the here proposed expression has been compared with those outcoming from other researchers and Code expressions, with respect to the test results found in the literature. The proposed expression has found to lead not only the most accurate but also the most uniform prediction of the column resistance under fire loads. It is also important to point out that the here proposed expression is very simple and easily applicable also by engineers in the practical design.