Local buckling of structural steel shapes

The objectives of this paper are to (1) provide analytical expressions for the elastic cross-section local buckling stresses, including element interaction, of hot-rolled steel structural shapes, and (2) compare these local buckling results to the assumptions inherent in the local slenderness limits of the US AISC structural steel specification. The cross-section local buckling stress is determined by finite strip analysis (FSA). Local stability of each cross-section in the AISC shapes database (excluding pipes) is considered in axial compression, as well as positive and negative bending about the major and minor geometric axes. Local buckling stresses are converted into plate buckling coefficients (kk’s) and simplified expressions are provided for all observed kk’s. The new kk’s explicitly include elastic web-flange interaction amongst the elements comprising the cross-section. The kk values from the FSA are compared to those inherently assumed in the AISC Specification, significant differences are observed.