Research on flexible honeycomb structure design for morphing aircraft

Abstract

The wing skins of the morphing aircraft would be highly anisotropic with low in-plane extending stiffness to fit the wing transformation and high out-of-plane bending stiffness to undergo the aerodynamic loads. A material mechanics method is presented to evaluate the elastic modulus properties of the U-shape honeycomb structures. The U-shape honeycomb structures were proved to have low in-plane axial stiffness and good load resistance in other directions. Both finite element analysis and experimental tests were carried out to verify the accuracy of the proposed analytical formulation. And a theoretical analysis solution also was developed, which could well compare with both experimental results and FEA results. And the Possion's ratio of the honeycomb structures was gained by FEA. It was also substantiated that U-shape honeycomb structures could be used for morphing aircraft wing skins.