Analysis for local buckling capacity of cold-formed steel sections with web opening

ADINA finite element solutions for the local buckling behaviour of C-shaped lipped channel cold-formed sections, with and without a large web opening, subjected to concentric axial load are presented. Isoparametric shell elements are used to model one-quarter of the sections. The web opening is generated using element birth/death option. The cold-formed steel has been treated as multi-linear elastic-plastic material with von Mises yield criterion. Material non-linear only analysis and material and geometrical non-linear analysis results are presented and compared with the experimental results. The ultimate loads are correctly predicted with 'the material and geometrical non-linear analysis. However, the predicted sub-ultimate behaviour does not agree well with the experimental results, perhaps due to the inherent imperfections.