Application of generalised beam theory to the study of the stability behaviour of laminated CFRP cylindrical stiffened panels

The paper presents the application of a novel fast numerical tool, based on Generalised Beam Theory (GBT), to perform buckling and post-buckling analyses of laminated CFRP panels. GBT is a beam theory developed for prismatic thinwalled members (e.g., columns, beams or panels), which takes into account both global and local deformations. One of its main features is the fact that the cross-section is discretised into deformation modes with clear mechanical meanings (e.g., global bending, distortional, local-plate, shear and transverse extension deformation modes) − this (i) allows for a better understanding of the member structural behaviour and (ii) makes it possible to perform analyses with very few d.o.f. (by preselecting a set of deformation modes). No stiffness degradation is taken into consideration and the material is deemed linear elastic and orthotropic. One presents numerical results concerning the local buckling and post-buckling behaviour of stiffened CFRP cylindrical panels, including one that was experimental and numerically investigated in the context of the COCOMAT project. The panel deformed configurations and buckling loads obtained with GBT are validated through the comparison with either experimental data or values yielded by shell finite element analyses carried out in the code ABAQUS.