Shear buckling of sandwich plates - Incompressible and compressible cores

Shear buckling behavior of sandwich panels with an incompressible and a compressible core is presented. The mathematical formulation includes various formulations for layered sandwich panel such as: Ordinary Sandwich Panel Theory (OSPT), High-Order Sandwich panel Theory (HSAPT) without in-plane core rigidity and with in-plane rigidity (HSAPT-A) Theory. The various models are based on a variational approach that yields the non-linear field equations and the appropriate boundary conditions. The high order model that takes into account the in-plane rigidity through the depth of the core, denoted as HSAPT-A, uses the accurate solution of the 3D elasticity problem involved. Linearization is achieved using a perturbation technique which yields equations for the pre-buckling and buckling stages along with the appropriate boundary conditions. A Galerkin solution type is adopted for all models and a closed-form solution through the depth of the core is used for the high-order case where the core rigidity is considered. A numerical study of a simply-supported panel with various layouts and dimensions and subjected to in-plane shear load is conducted. The results include bifurcation loads and mode shapes (3D or contour plots) of the displacements, internal stress resultants and interfacial stresses at face core interfaces. (C) 2016 Elsevier Ltd. All rights reserved.