Dynamic Modeling and Simulation of Morphing Wing Aircraft Considering Rigid-Elastic Coupling Effects

During the morphing process, the dynamic modeling of the morphing wing aircraft presents the characteristics of rigid-elastic coupling effects, moving boundaries, and low computational efficiency. Meanwhile, parameters such as aerodynamic forces/moments, center of pressure, center of mass, and moment of inertia would also change significantly, which would seriously affect the flight stability. Therefore, this paper mainly focuses on the rigid-elastic coupling dynamic modeling of morphing wing aircraft. Based on the virtual power principle, a floating coordinate system and the modal synthesis method are adopted to establish a rigid-elastic coupling dynamic model that accounts for the elasticity of the wings, which can accurately capture the cross-scale coupling effects between the rigid-body motion and the elastic deformation of the wings during the continuously morphing process. Considering the moving boundary problem between the fuselage and the wings during the continuously morphing process, a dynamic constraint modeling technique based on the Craig-Bampton method and a node's life and death technique describing the constraint states are proposed, which can avoid the complex operations of reestablishing the finite element model of the elastic bodies for traditional methods. Moreover, a method of smoothing model for the rigid–elastic coupling system is developed, which can significantly improve the computational efficiency for the dynamic equation of the morphing wing aircraft. And by changing the value of the smoothing factor, preservation of specific high-frequency components can be controlled. Finally, the numerical examples are carried out to verify the proposed rigid-elastic coupling dynamic model for the morphing wing aircraft.