Optimization of compliant adaptive structures in the design of a morphing droop nose

A design procedure for the synthesis of active camber morphing wing devices is proposed. A topology optimization initially defines the internal structure that is further enhanced by structural size and shape optimizations, and these optimizations are based on the distributed compliance concept. The size optimization enables the adaption of the topology solution to other materials and geometries while refining the topology solution to improve the shape quality of the skin deformation. Then, the structural shape optimization enables the reduction of the stress peaks inside the compliant structure and the finalization of the details to obtain a solution that is closer to the manufacturing process stage. The proposed methodology is used in the design of an adaptive droop nose to be installed on a reference regional aircraft, and two different design applications are considered. The first application is the validation of the procedure at the full scale level using a superelastic material for the internal structure. The second application is the design of a corresponding 3D-printed prototype, in which both geometry and material changes are considered, for experimental validation. The results show satisfactory shape quality and the achievement of structural feasibility. The experimental functional test of the scaled prototype demonstrates the effectiveness of the adopted morphing solution.