GBT local and global buckling analysis of aluminium and stainless steel columns

A non-linear elastic Generalised Beam Theory (GBT) is formulated and used to investigate the buckling behaviour of aluminium and stainless steel thin-walled columns. The modifications that must be incorporated in the conventional GBT, in order to handle the material non-linearity, are addressed and particular attention is paid to the need to define the stability problem in terms of instantaneous elastic moduli. After validating the proposed GBT, by means of its application to compressed rectangular plates, the unique features and capabilities of the theory are illustrated through the presentation and discussion of results concerning C-section and RHS columns. Stress–strain laws of the Ramberg–Osgood type are used to model the uniaxial behaviour and both J2-flow and J2-deformation plasticity theories are implemented.