Global-distortional buckling mode influence on post-buckling behaviour of lip-channel beams

The paper deals with nonlinear buckling analysis of thin-walled lip-channel section beams subjected to pure bending. The short and medium length beams made of steel and laminates have been considered. The special attention has been paid on interactive buckling with local, primary and secondary global-distortional modes. The influence of different buckling modes as an initial geometrical imperfection on postbuckling behaviour have been analysed. The semi-analytical method (SAM) has been employed. Additionally, a new FEM model was developed to verifying results obtained from SAM. This validation was helpful to find the range of application of SAM.