The effect of residual stresses in the lateral-torsional buckling of steel I-beams at elevated temperature

When a beam is bent about its major axis, it may twist and move laterally, before it reaches its elastic/plastic resistance in bending. Although the problem of lateral-torsional buckling of steel beams at room temperature has a well-established solution, the same problem at elevated temperature has not. A numerical investigation of the lateral-torsional buckling of steel I-beams subjected to a temperature variation from room temperature up to 700 degreesC, with the aim of assessing the effects of the residual stresses in this mechanism of failure, is presented in this paper. To this purpose, a geometrically and materially non-linear finite element program has been used to determine the lateral-torsional resistance of steel I-beams at elevated temperatures, using the material properties of Eurocode 3, Part 1-2. The numerical results have been compared to the results of the simple model presented in Eurocode 3, Part 1-2 (1995) and a new proposal that is being considered for approval. (C) 2003 Elsevier Ltd. All rights reserved.