MORPHING FORWARD WING SECTION SKIN DESIGN FOR A SAILPLANE CONSIDERING WING BENDING

A sailplane with a morphing forward wing section promises a significant perormance increase compared to conventional designs. The morphing skin shall adopt the desired aerodynamic shapes for fast and slow flight, that are imposed by discrete ribs with compliant mechanisms. These shapes shall also be achieved in between those ribs. For high-aspect ratio wings on sailplanes, spanwise bending deformation s significant and the morphing shell must not buckle or fail. Also a low deformation energy for morphing and a low mass are desired. Studies show different results for a quasi-2D jig-shape compared to a wing with increasing spanwise bending, where bending deformations in two directons are superimposed. A modelling and analysis approach s shown that considers these 3D effects. A FEM simulation of a representative wing segment is performed and the resulting elastic airfoil shapes at several flight conditions are analyzed geometrically and aerodynamically. Monolithic shell laminates with balanced ply angles show promising behavior and are chosen as a baseline design. Fiber material, thickness and angle are chosen as design variables for a parameter study for this multi-objective problem. With a stiffness analysis of the laminates, possible correlations between stiffness parameters and objectves are investigated. The optimum skin aminate depends on the chosen objective priorities.