GBT Buckling Analysis of Cylindrical Panels Under Compression

This paper presents a study on the buckling behaviour of curved panels under pure compression using the Generalised Beam Theory (GBT). A GBT formulation is presented first, based on its natural degrees-of-freedom (i.e. modes) and some explanations are given about the discretization of panel section and its influence on the deformation mode nature. Then, the GBT formulation is applied and illustrated by means of three studies. In the first study, the influence of the deformation mode (global, distortional, local, warping shear, transverse extension) on the buckling load and buckling mode of an unstiffened panel with moderate curvature is investigated. Then, in the second and third studies, the effects of the curvature and of the number of stiffeners on the buckling behaviour of the panels are assessed. It is concluded that accurate predictions of buckling loads and modes of curved panels can only be achieved by considering all modes (conventional, warping shear and transverse extension) in GBT analyses. Both warping shear and transverse extension modes appear naturally due to the panel curvature. However, their participation drops with decreasing curvature of the panel – in the limit case (flat panel, i.e., plate) their contribution is null and only conventional modes participate in the buckling mode (minor axis bending and distortional modes tend to equal participations, 50% each). Finally, an increase of the number of stiffeners leads to a decrease of the global mode participation and to an increase of the distortional mode participation.