Nonlinear flange curling in wide flange sections

The paper describes the experimental and theoretical analysis of flange Curling deformations in wide flange sections. As distinct from previous analyses of flange Curling, the paper considers the effect of cross-sectional deformations in the calculation of the cross-section stress distribution and the flange Curling deformations. The deformations of the cross-section lead to changes in the second moment of area of the cross-section and its neutral axis, and the analysis is therefore iterative. It is shown that the effect of flange Curling is to decrease the applied stress near the centre of the wide flange, which in turn increases the buckling capacity of the section. Of particular interest is the finding that while the stress distribution changes significantly, the final flange curling deformation is virtually the same whether obtained from ail accurate iterative analysis or from a first-order linear analysis. This provides a simple improved method for determining the effects of flange Curling, namely by determining the flange curling deformations from a first order analysis and accounting for them in determining the stress distribution. (C) 2008 Elsevier Ltd. All rights reserved.