Buckling and wrinkling of anisotropic sandwich plates

The global buckling and wrinkling behavior of sandwich plates with anisotropic facesheets is investigated by means of a linearized stability analysis. High-order plate models are formulated referring to a sublaminate variable-kinematic approach: an axiomatic through-thickness description of the displacement field is introduced, wherein the selected model is employed for an arbitrarily defined group of plies, i.e., the sublaminate. The two-dimensional governing equations of the plate model are solved in weak form by means of the Ritz method. The modeling approach is applied to sandwich plates with anisotropic laminated facesheets and orthotropic cores. A wide set of configurations is analyzed: critical loads and wrinkling patterns are determined for panels with foam and honeycomb cores, subjected to uniaxial as well as multiaxial loads. The proposed approach is shown to provide accurate, quasi-3D predictions for both long and short wavelength buckling with a reduced computational effort.