Global buckling load calculation of the of sandwich conical shells with lattice cores subjected to axial compression loading using a novel smeared method

In the present paper, an analytical model was presented according to a novel smeared stiffener approach in order to predict the global buckling load of composite sandwich conical shells with lattice core subjected to axial compression loading. The sandwich panel was made up of two skins and a lattice core. A smeared method was developed to approximate the lattice core with an equivalent composite shell. First, using the forces and moments analyses of a unit cell, the stiffness contribution due to the lattice were determined and then superimposed with those of the inner and outer skins in order to obtain the stiffness parameters of the whole panel. The governing equations were extracted according to the classical shell theory of Donnell type. Galerkin method was employed to obtain the buckling loads of the composite sandwich conical shells. A 3-D finite element model was also created using ABAQUS software in order to validate the analytical results. The comparison of the results indicated a good agreement between the two implemented methods and revealed that the proposed analytical model is accurate enough to predict the buckling behavior of sandwich conical shells with lattice core.