Constrained flexible wing with folding wingtip dynamics model based on Lagrange's method

ifasd2024 Tracking Number 149

One way of reducing an aircraft’s induced drag while meeting airport gate limitations is increasing the wingspan and introducing a folding wingtip. By making the hinge flexible and rotating it’s axis outboard the folding wingtip could be used to reduce gust loads. As aircraft are becoming more flexible, the flexibility is another important factor that needs to be considered. In the following a set of equations of motion describing a constrained flexible wing with a flared folding wingtip, that considers follower forces of the wing and folding wingtip as well as the geometric exact angle of attack is derived using Lagrange’s method considering the folding wingtip as separate body. The formulation is used to set up an aeroelastic model in MATLAB/Simulink. The model is tested on the TU-Flex wing with a hinge introduced at 80% span and compared to the original wing. It can be shown that the folding wingtip dynamics have an influence on the stability of the system reducing the damping of the modes and introducing a new lower frequency mode.