Elastic Distortional Buckling of Singly Symmetric I-shaped Flexural Members With Slender Webs

The effectiveness of the measures provided in the 2005 American Institute of Steel Construction (AISC) Specification for elastic distortional buckling of doubly symmetric I-shaped flexural members with slender webs was evaluated in a previous study. It was demonstrated that the code equations generally provide conservative strength estimates for the slender-web I-beams, and the amount of the conservatism was found to be rather dramatic for some cases. As a continuation of this effort, the effectiveness and accuracy of the 2005 AISC code provisions as well as predictions for elastic distortional buckling of slender-web singly symmetric I-shaped members is investigated in this paper. Comparisons are made with the finite strip analysis results for distortional buckling and the two design equations for elastic distortional buckling proposed by other researchers. It is demonstrated that the code predictions are by and large conservative, and even overly conservative in some cases, which does not seem to be justifiable economically.