The aim of the work is the evaluation of the ultimate behaviour of aluminium channel sections subjected to local buckling under uniform compression. In particular, two different approaches are presented to predict the inelastic response of aluminium members: the Deformation Theory of Plasticity (DTP) and the Effective Thickness Method (ETM). The first one represents a theoretical procedure applied according to elastic-plastic stability theory of a single plate and considering restraining effects of adjacent plate elements. The Effective Thickness Method (ETM) is a simplified approach currently adopted by Eurocode 9 to estimate the ultimate resistance of aluminium sections taking into account the local buckling effects. In this paper, an ext...