A Smooth Shear-Deformable Pre-Stretched Skin: Design and Mechanical Analysis

In shear variable-sweep wings, conventional skins cannot sustain smooth deformation.In order to maintain the aerodynamic shape of a shear variable swept-back wing, this paper is devoted to the development of a pre-stretched flexible skin. The skin can maintain smooth deformation during shear deformation and withstand aerodynamic loads through pre-stretching. The pre-stretched flexible skin includes two parts: a pre-stretched silicone rubber surface that can be smoothly and continuously sheared and a carbon fiber support structure that can bear the aerodynamic load. Based on the buckling theory and Hamilton’s principle, the mathematical model is developed for the critical shear angle, out-of-plane stiffness and shear-driving force of pre-stretched flexible skins with the in-plane shear loading and aerodynamic loading. A systematic comparison between the theoretical solutions and the numerical simulation results is carried out to validate the excellent accuracy and reliability of the numerical evaluations. The effects of geometric parameters on the out-of-plane stiffness, shear-driving force and critical shear angle of pre-stretched flexible skins are systematically studied. The results show that this pre-stretched flexible skin has better aerodynamic performance.