Research On Optimization And Performance Of The Flexible Skin For Morphing Wing

The flexible skin in recent years became the one of the hot spots for the morphing aircraftresearch. Because morphing aircraft requests the wing skin to achieve continuous smoothdeformation and withstand large aerodynamic loads, therefore, selected a kind of corrugated-formwhich has good deformation capacity in the longitudinal direction and show resistance againstbending loads in the transverse to study. The main research content of this paper is about thefollowing:Firstly, this thesis discussed feasible direction optimization methods and described how to enablethe target function to reach the optimal point in engineering optimization. Then, it used thisoptimization method to conduct optimization design on the cross-section shape and the ply orientationangle of the standard semi-circle skin matrix. Based on optimization results, simulation and analysisof stretching and three-point bending was made by utilizing the finite element analysis softwarePatran/Nastran and comparison was made to the original corrugated skin. Simulation results show thatthe elongation at stretching of the skin matrix after optimization was twice the original corrugatedskin and the bearing deformation was reduced by44.1%. Based on the optimized shape, a moldprocessing stretching specimens and three-point bending specimens was designed and skin testsamples of the original corrugation and the optimized one were prepared. The samples uses themanual molding technology. Through stretching testing and three-point bending testing, the accuracyof simulation was verified.Secondly, curve fitting was conducted on the corrugation obtained via optimization and based onits fitting formula, mechanical analysis was made on the skin under the stretching load. Amulti-channel strain sensing and measuring system was designed. This system is composed of asensor module and a PC data processing module. Stain of the optimized skin under the stretching loadat all peaks and valleys was tested by using this system and its mechanical analytic model wasvalidated.Finally, in this paper, a NACA0012shape-based flexible trailing edge mechanism was designedand its airfoil surface was covered with the optimized corrugated skin. Through measuring therelationship between strain of the skin peak and the deflection angle of the trailing edge, experimentaldata were offered to the inversion of flexible edge.