High-altitude and long-endurance UAVs, distributed electric propulsion aircraft and large passenger aircraft often use high-aspect-ratio wings, which have obvious geometric nonlinear large deformation effect, and are usually arranged with a certain number of external stores, which have an impact on their geometric nonlinear aeroelastic characteristics. Based on the “quasi-linear” hypothesis, the updated Lagrange incremental finite element method and doublet-lattice method are used to perform the geometrically nonlinear static aeroelastic analysis, and the mass, stiffness and aerodynamic matrices of large deformation are updated, and the geometrically nonlinear flutter characteristics of high-aspect-ratio wings are calculated. The influence of the position and mass of the external store on geometrical nonlinear flutter characteristics of high-aspect-ratio wing structure is investigated. Results show that the change of the position and mass of the external store causes the relative position between the elastic axis and the center of gravity of the wing, and the wing’s large deformation equilibrium state to change, resulting in differences in the stiffness characteristics of the wing and the natural vibration frequency of the equilibrium state, thus affecting the wing flutter characteristics. When a single external store is installed near the wing root, changing the mass and direction of the store has no significant effect on the geometric nonlinear flutter characteristics of the wing. The improvement of wing flutter speed is most obvious when the hanging point is moved to the leading edge of the wing near 0.65 times the wingspan.

Traditionally, the internal of aircraft wings is generally straight spars and ribs. The use of curvilinear spars and ribs (SpaRibs) on the wing can greatly broadens the design space and further improve the aeroelastic performance. An aeroelastic comprehensive optimization design method is proposed for flying-wing aircraft with SpaRibs based on genetic algorithm. The supersonic double lattice method is used to calculate the unsteady aerodynamics, and the modal method is used to carry out the static aeroelastic analysis The flutter velocity is optimized by considering the static aerodynamic deformation constraint. A comprehensive optimization design calculation example of a flying wing aircraft shows that the flutter velocity can be increased by 20.34% on the basis of a weight increase of 1.321% for a wing with a SpaRibs structure. It provides a new idea for the system design of the flying wing aircraft structure and project a fast and effective aeroelastic comprehensive optimization design method.