Design and Shear Analysis of an Angled Morphing Wing Skin Module

Abstract

Morphing wing skin can greatly improve the performance of aircraft by adjusting the shape of the wings according to different flight conditions. However, it is a challenge to maintain a smooth aerodynamic wing skin surface during the deformation process. Here, we propose an angled morphing wing skin module based on a silicon rubber matrix reinforced by carbon-fiber-reinforced polymer rods, which takes advantage of the tensile stress generated during shear to prevent it from wrinkling under large shear deformation. Experiments conducted on a series of wing skin modules with varying initial angles indicate that by starting from an angled configuration, the skin module can withstand a pure shear deformation of 92° without wrinkling, 53% larger than existing designs. A parametric analysis was also conducted to analyze the effects of geometric and material parameters on the wrinkle-free deformation range. Finally, a theoretical model based on the energy method was developed to unveil the underlying wrinkle prevention mechanism and to estimate the critical wrinkling angle of the skin. The proposed design can potentially greatly expand the shear morphing capability of aircraft wings, leading to larger variation in sweepback angle and therefore superior aerodynamic performance.