Research On Design And Manufacturing Of Honeycomb Structure Of Morphing Structures

Morphing wing,a key component in the morphing aircraft,is required to be flexible,loadbearing,lightweight and high strength.The honeycomb structure is characterized by its light weight,strong designability and excellent mechanical anisotropy.Compared with the positive Poisson’s ratio honeycomb structure or the negative Poisson’s ratio honeycomb structure,the zero Poisson’s ratio honeycomb structure will not be saddle or auxetic shape during deformation process.Thus,the zero Poisson’s ratio honeycomb structure can be used as subsupport sructure in morphing wing.The combination of hyperelastic materials and honeycomb structure is recognized as the most promising flexible wing structure in the field of morphing aircraft.In this dissertation,a new type of zero Poisson’s ratio honeycomb structure is proposed.The zero Poisson’s ratio honeycomb structure is preparated by carbon fiber composite and analyzed its mechanical performances.The application of the novel honeycomb structure in the morphing aircraft is studied.The main research contents of this paper are as follows.Firstly,a novel zero Poisson’s ratio honeycomb structure was proposed.The multi-scale analysis method of structure genome mechanics was employed to homogenize the honeycomb unit cell structure,and the equivalent elastic properties of the overall honeycomb structure were obtained.The refined finite element model of the honeycomb structure was carried out to verify the in-plane elastic modulus predicted by the mechanics of structure genome.The influence of the geometrical parameters of the honeycomb structure on the equivalent elastic modulus of the structure was analyzed.Compared with the star honeycomb structure,the novel honeycomb structure can maintain zero Poisson’s ratio and has better in-plane deformation and resistance to out-of deformation.Secondly,the zero Poisson’s ratio honeycomb structure was prepared by carbon fiber composites and the interlocking method.The mechanical performance tests of the honeycomb structure under in-plane compression and three-point bending were carried out The ultimate loads of the carbon fiber composite honeycomb structure under the two load conditions were obtained.The failure analysis of the honeycomb structure was carried out by the finite element method.The influences of composite layup and geometric parameters on the ultimate load were discussed.Compared with the 3D printing process,the interlocking assembly process has advantages in preparing carbon fiber composite structures and can better play the role of composite materials advantage.Finally,in order to achieve the wing with a variable camber trailing edge,the novel zero Poisson’s ratio honeycomb structure was used as the substructure,the silicone rubber hyperelastic material and the corrugated structure were used as the flexible skin,and pneumatic muscle was used as the actuator.The theoretical analysis,FEM method and experiment were employed to investigated the wrinkle phenomenon of the flexible skin under bending.A method of the partial thickening of the silicone rubber skin was proposed to suppress the wrinkle.The key components of the camber morphing wing were preparated and assembled..Through the deformation test of camber morphing wing,the feasibility of the novel honeycomb structure and the method of wrinkle suppression in the morphing wing has been verified...