Design and analysis of flexible skin based on zero Poisson’s ratio hybrid honeycomb

摘要

Morphing aircraft can change external shape in flight according to different flight environments and tasks, and improveflight performance maximumly. Among them, the morphing wing can improve the aerodynamic performance efficientlyand has become one of the hot spots in recent years. One of the key technologies for morphing wing is flexible skintechnique. Aiming at the conflict between in-plane deformation and out-of-plane bearing capacity of flexible skinstructure design, a zero Poisson's ratio hybrid honeycomb structure was designed. The strips are added to the honeycombstructure to form a hybrid honeycomb, which increases the out-of-plane bending stiffness. Three different shapes ofhoneycomb grid elements were proposed, which are cruciform, square, and H-shaped. By adjusting the shape and sizeparameters of the three kinds of honeycomb grid elements and the height and quantity of the laying strips, the in-planedeformation mechanism of each element was analyzed by the representative volume element method, as well as thevariation of mechanical properties with the element and strip shape parameters. The mechanical properties of the hybridhoneycomb structure were analyzed by finite element simulation. Considering the requirements of the variable cambertrailing edge wing, a flexible skin which has capacity of out-of-plane bending resistance was constituted by coveringelastic panel over the surface of zero Poisson's ratio hybrid honeycomb. The flexible skin structure has good airtightnessand smooth surface. Also, it meets the requirements of in-plane unidirectional deformation along with out-of-planebearing capacity.