On buckling loads for edge-loaded orthotropic plates including transverse shear

Corrugated board usually exhibits low transverse shear stiffness, especially across the corrugations. In the present study the transverse shear is included in an analysis to predict the critical buckling load of an edge-loaded orthotropic linear elastic sandwich plate with all edges simply supported. In the analysis, effective (homogenised) properties of the corrugated core are used. Classical elastic buckling theory of orthotropic sandwich plates predicts that such plates have a finite buckling coefficient when the aspect ratio, i.e. the ratio between the height and width of the plate, becomes small. However, inclusion in the governing equilibrium equations of the additional moments, produced by the membrane stresses in the plate at large transverse shear deformations, gives a buckling coefficient which approaches infinity when the aspect ratio goes to zero. This improvement was first included in the buckling theory of helical springs by Harinx [Proc. Konjlike Nederland Akademie Wettenschappen, vol. 45, 1942, Amsterdam, Holland, pp. 533-539, 650-654] and later applied to orthotropic plates by Bert and Chang [J. Eng. Mech. Division, Proc. Am. Soc. Civil Engrs. 98 (EM6) (1972) 1499-1509]. Some inconsistencies in the latter analysis have been considered. The critical buckling load calculated with corrected analysis is compared with a predicted load obtained using finite element analysis of a corrugated board panel, and also with the critical buckling load obtained from panel compression tests. (C) 2003 Elsevier Ltd. All rights reserved.