Buckling of prismatic structures under biaxial loading

This work presents an analysis and numerical results for the buckling of longitudinally stiffened prismatic structures that consist of an assemblage of flat plate and cylindrical panel components. The applied loading is assumed to induce uniform in-plane biaxial stresses, and all types of buckling modes (general, local, and coupled) are automatically accounted for in the analysis. Previous analyses of such problems by the exact (Wittrick) and approximate (Cheung) finite strip methods are based on the assumption that the structure is simply supported on the transverse ends by diaphragms (SS3 classical simple supports). The present work extends these analyses to include the case of completely clamped transverse ends (CC4), as well as simply supported ends. A one term Galerkin method is used to replace the governing partial differential equations of equilibrium for each component by ordinary differential equations in terms of the transverse coordinate, and the ordinary equations are solved exactly. The principle of virtual work is employed to obtain the stiffness matrix for each component. Numerial results are presented for a wide variety of CC4 and SS3 prismatic structures. These results compare favorably with available solutions.