Overall buckling of typical thin-wall sandwich composites applied on the aircraft

In order to study the feasibility of applying typical thin-wall sandwich composite without ribs and frames reinforcement on the aircraft fuselage, overall buckling performance of the honeycomb sandwich composite under the in-plane compression and shear load was studied using analytical method, finite element method (FEM) and experiment. Based on the classical laminated plate theory and the engineering analytical method, the variation of the buckling load of honeycomb sandwich composites with the sample size was given and compared with the finite element results. Two typical sizes of sandwich structure were designed, and boundary conditions and loading methods were defined based on a certain type of typical aircraft fuselage structure. Finally, the buckling loads obtained by analytic solution and FEM were compared with the experimental results, which verified the bearing capacity and failure mode of the typical thin-wall sandwich structure. The results show that the test compression failure mode is consistent with the theoretical prediction, so the overall buckling load calculated through the three methods is almost equal to each other. Because local failures occur in the shear test, so the experimental result is lower than FEM result and analytic result. However, the FEM results and the analytical results are consistent, which could verify their effectiveness. And it's found that the analytical method is relatively conservative.