Transfer Function Method for the Nonlinear Flutter of a High-aspect-ratio Wing

Abstract

Abstract-The semi-analytical and semi-numerical transfer function method is applied to the nonlinear flutter of a high-aspect-ratio aircraft wing. Firstly, the flutter differential equation of a three-dimensional wing is established by combining the bend-twist vibration equations of the wing and the ONERA nonlinear aerodynamics model for wings. Then, using the transfer function method, the control equations are formulated in a state-space form by defining a state vector. Both the flutter velocity and flutter frequency are obtained by solving a complex eigenvalue problem. Finally, the differences of the flutter behavior of the linear and nonlinear aerodynamic models under the influence of parameters such as mass of unit length, semi-aspect ratio, the stiffness ratio of twist and bend are discussed.