Versatile absolute nodal coordinate formulation model for dynamic folding wing deployment and flutter analyses

Aircraft performance can be improved using morphing wing technologies, in which the wing can be deployed and folded under flight conditions, providing a wide flight envelope, good fuel efficiency, and reducing the space required to store the aircraft. Because the deployment of the wing is a nonlinear-coupled motion comprising large rigid body motion and large elastic deformation, a nonlinear folding-wing model is required to perform the necessary time-domain deployment simulation, while a linear model is required to perform the frequency-domain flutter analysis. The objective of this paper is to propose a versatile model that can be applied to both the time-domain and frequency-domain analyses of a folding wing, based on flexible multibody dynamics (MBD) using absolute nodal coordinate formulation (ANCF) and unsteady aerodynamics. This new versatile model expands the application range of the flexible MBD using ANCF in time-domain simulation, allowing it to express the coupled motion of extremely large elastic deformations and large rigid body motions that arise in next-generation aircraft. The time-domain deployment simulation conducted using the proposed model is useful for parametric deployment-system design because the model has improved calculation time. In the frequency-domain flutter analysis of a folding wing, the flutter speed obtained from the proposed model agrees with that obtained from an experiment, with an error of 4.0%, showing promise for application in next-generation aircraft design.