Aircraft wing panel buckling analysis: efficiency by approximations

A comparison of ‘exact’ and approximate methods for the determination of critical buckling loads of prismatic benchmark metal and composite panels is presented. The panels are stiffened by either J-, blade- or hat-stiffeners and are representative of typical aircraft wing panel configurations, with in-plane shear and compression load combinations. Buckling design curves and modes are illustrated and associated CPU times are given to demonstrate the accuracy and efficiency of the approximations adopted. Initial results for the benchmarks, which are rectangular in plan-form, are compared with rigorous finite element solutions. Thereafter, attention is focused on results for the same panels but with parallelogram plan-form. Two analysis methods based on Classical Plate Theory are used as follows: an existing, ‘exact’ method incorporating Lagrangian multipliers to constrain the transverse (or skew) boundary conditions; and a recently developed approximate infinite width technique based on the previous one but analysing only a repeating portion of the plate assembly