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 appr
oximation adopted. Initial results for the benchmarks, which are recta
ngular in plan-form, are compared with rigorous finite element solutio
ns. Thereafter, attention is focused on results for the same panels bu
t with parallelogram plan-form. Two analysis methods based on Classica
l Plate Theory are used as follows: an existing, 'exact' method, incor
porating Lagrangian multipliers to constrain the transverse (or skew)
boundary conditions; and a recently developed approximate infinite wid
th technique, based on the previous one but analysing only a repeating
portion of the plate assembly. (C) 1998 Elsevier Science Ltd. All rig
hts reserved.