Shear-Flexible Orthotropic Plates Loaded in Plane

A new, improved theory is presented for orthotropic plates with thickness-shear flexibility and subjected to in-plane loading. The improvement introduced herein is the modification of the slopes at which the in-plane stress resultants are assumed to act. This is a generalization of the work of Haringx from columns to inplane-loaded plates. Comparison with the classical (Reissner) shear-flexible plate theory shows that the improved theory imposes loading anisotropy on the governing differential equations and tends to predict higher buckling loads than the overly conservative Reissner theory. Comparison with experimental results for uniaxially-compressed, simply supported sandwich plates with glass-fiber-reinforced facings and hexagonal-cell honeycomb cores indicates that the improved-theory results agree slightly better than do the Reissner-theory results.