Global buckling and wrinkling of variable angle tow composite sandwich plates by a modified extended high-order sandwich plate theory

The advanced Automated Fibre Placement (AFP) manufacturing technologies make the synthesis of Variable Angle Tow (VAT) composites, which enable design lightweight sandwich structures to possess variable stiffness facesheets. However, both global and local instability phenomena VAT plates under in-plane compressive loads are rarely explored till now. objective this article is fill gap by developing a Rayleigh–Ritz procedure based on modified extended high-order plate theory (EHSAPT). original two-dimensional EHSAPT proposed Phan et al. (2012) three-dimensional case with minor modification that first-order shear deformation instead classical Kirchhoff–Love hypothesis adopted for each facesheet, brings several merits such as conciseness in derivation process easiness program implementation. approach combined principle minimum potential energy employed derive eigenvalue equation governs problem loads. Both buckling wrinkling patterns can be captured analytical model framework. Before analysis, nonuniform prebuckling stresses over entire determined assumption membrane state. usage Lagrange multiplier method regime removes restrictions inherent conventional formulation thus provides general way boundary conditions. accuracy effectiveness developed validated comparing previously published results FE solutions given ABAQUS. Effects core thickness, orthotropy, fibre orientation angle facesheets behaviour investigated. Finally, mechanism steering trajectory improve resistance studied discussed.