Morphing aircraft wings are one of the proposed solutions to reducing aviation’s environmental impact as they seek to improve the aircraft’s aerodynamic efficiency and thereby reduce green-house gas emissions. The competing structural requirements of morphing skins, which are required to have a high out-of-plane stiffness to resist aerodynamic loading and a low in-plane stiffness to keep the actuation energy low, are one of the key reasons why this technology is not yet being deployed on a large scale. The novel Geometrically Anisotropic Thermoplastic Rubber (GATOR) morphing skins introduced by these authors seek to take advantage of multi-material 3D printing and structural scaling laws to allow for better compromises between the competing design constraints.
In this work, a finite element study of the novel GATOR skins is presented exploring the fundamental relationships between skin configuration and performance of a GATOR skin panel consisting of two face sheets and a zero Poisson’s ratio Morphcore using a numerical model comprised of second-order 3D elements and 2D first-order elements to model the core and the skin, respectively which was validated with experimental results. The GATOR skin is divided into 6 unique design parameters: core height, bending member thickness, core thickness, bending member angle, the distance between the unit cells, and skin thickness. A detailed design space analysis shows how those parameters influence the performance metrics such as axial and bending rigidity and mass properties to better understand what effect they have on those competing design requirements and how they can be used in a targeted way to optimize a GATOR skin.