Abstract

High-lift devices like slats and flaps have been used for a long time to improve the performance of the aircraft depending on the flight conditions. Wingtip and winglet have become popular solutions to decrease the drag coming from wing tips vortices and to increase the fuel efficiency. These components are assembled on the wing box structure to form the full wing. Classical high-lift devices are expensive, complex and heavy. They are therefore not acceptable solutions for the current trends on efficient and green aircrafts. Recent developments based on adaptive/morphing structures may overcome the limitations of classical high-lift devices, and so provide better solutions while reaching the objectives in terms of efficiency and environmental impact; furthermore, control laws of wingtip and winglet surfaces may be defined in order to obtain a wing loading control and alleviation system (LC&A technologies). The idea is to adapt the shape of the wing to the flight condition by using morphing techniques. The compliant and/or kinematic mechanisms as well as the actuation system are now inserted in the wing and used to change its shape. Using morphing concepts allows shape change without generation of discontinuities in the flow (no aerodynamic gap). This paper presents the activities undertaken in the DEMMOW project (CleanSky 2, n°755621). The goal of the project was to develop a high fidelity integrated non-linear MBS-FEM model of a morphing wing, including several structural components (composite box, morphing winglet, droop nose and adaptive trailing edge), with kinematic joints and actuators. Multi-body dynamics modelling of the mechanical system is addressed by the finite element method extended to multi-body systems including flexibility and non-linearities related to large displacements and rotations, and to morphing parts that can include compliant structures and non-linear materials, leading to a flexible wing concept. The paper will highlight the development of the finite element models of the separate morphing components (morphing winglet, droop nose and adaptive trailing edge). Comparison to ground test results will be provided.