05.19: Lateral‐torsional buckling of steel beams with tapered flanges and web

ABSTRACT Tapered steel beams are commonly applied in modern steel structures due to their less weight and more optimal solutions of the structural designs. That is why effective engineering solutions of the problem of their lateral‐torsional buckling is expected. In the paper a procedure to solve the problem of calculating critical buckling moment of a tapered beam is proposed with the application of potential energy calculations using Ritz method. Respective solution allows to obtain critical moments initiating lateral buckling of the simply supported, modestly tapered steel I‐beams. In particular, lateral‐torsional buckling of beams with tapered flanges and the web are considered. Detailed, numerical, parametric analyses are carried out. Typical engineering, uniformly distributed design loads are considered for load applied to the top flange, shear centre, as well as to the bottom flange. The parametric analysis of beam with tapered cross‐section, demonstrates that tapering of flanges influences much more the critical moments than tapering of the web.