Buckling modes identification from FEA of thin-walled members using only GBT cross-sectional deformation modes

• Buckling shell FEA of thin-walled members yields critical loads and modal shapes.
• First step of GBT yields the cross-sectional deformation modes (CSDM).
• Buckling fundamental modes are extracted from FEA using CSDM.
• Global, Distorsional and Local mode participations are obtained.

This paper presents the latest developments of an original method based on Generalized Beam Theory (GBT) capable to identify the fundamental deformation modes of global, distorsional or local nature, in general buckling modes provided by the shell finite element analysis (FEA) of isotropic thin-walled members. This method has the advantage of using only the GBT cross-sectional deformation modes instead of the member base mode shapes. The participation of each fundamental buckling mode can be calculated, allowing an accurate and quantitative evaluation of the coupled instability. There are no restrictions regarding the element cross-sectional shape, loading and quite recently discovered, boundary conditions.