Behaviour of axially loaded lipped channel

Abstract

Thin plates have a stable post buckling behaviour so that its failure load is materially higher than its buckling load. This characteristics makes thin plates very suitable structural elements in lighweight structures. For a thin-walled channel which consists of a system of connected thin plates, the structure will develop local, torsional, flexural buckling or a combination of these modes under axially compressive loads. Either buckle of an individual plate component or buckle as a system of connected plates may cause a reduction in the stiffness of the section. Hence, a lower load carrying capacity is expected. In this paper, the finite strip method is employed to investigate the buckling behaviour of axially loaded lipped channels. In the formulation, by modifying the displacement function, the buckling solution of other end support conditions besides the simply supported case is obtained. Furthermore, utilizing the eigenvectors from the elastic buckling solution, the lower bound method is used to evaluate the initial post buckling stiffness of an adequately edged stiffened thin-walled channel.