Design rules for lateral torsional buckling of channel sections subject to web loading

Channel sections are widely used in practice as beams. However, design rules for eccentrically loaded (not through shear centre) beams with channel cross-sections are not available in Eurocode 3. In this paper five proposed design rules are summarised, explained and their validity is checked by Finite Element analyses. The design rules yield ultimate loads that are compared to ultimate loads from geometrical and material nonlinear analyses of imperfect (GMNIA) beams with channel cross-sections. A parameter study is performed by varying the dimensions of the cross-section, the span length to section height ratio of the beams, the type of loading and the point of load application but is limited to load application through the web of the channels. Based on one of the proposed design rules, this study has led to a new design rule which conforms to Eurocode 3.