The effects of structural nonlinearity on the dynamic response to aeroelastic gust models

This paper investigates the influence of structural non-linearities on worst-case gust load predictions. The non-linear aeroelastic equations are solved using an extended harmonic balance method, recently proposed by the authors, and direct time integration of the aeroelastic system with the rational function approximation of the aerodynamic model. First, the results obtained by two methods are compared and the limitations of the proposed method are discussed. Then, the time integration method is used to show how structural non-linearities and uncertainties affect the critical loads conditions. The results are illustrated using a two-dimensional aeroelastic model with non-linear heave and pitch springs. The two-dimensional model is equivalent to a full aircraft aeroelastic model which closely approximates the Airbus A330 aircraft model.