A Superposition Method for Calculating the Aeroelastic Behavior of Swept Wings

This paper presents the development and application of a method for solving aeroelastic problems on sweptback wings, primarily suitable for use by aerodynamicists and structural design engineers. This method, called, the "superposition method," separates the aerodynamic and structural calculations, making it possible to use either theoretical or experimental determinations of spanwise loading and to account for induction effects. The method has been developed principally for use in design calculations where simplicity and rapidity of solution are primary considerations. First, certain selected initial twist distributions are applied to the wing. For these, the spanwise loading is determined and the elastic deflections are computed. Any arbitrary loading may then be calculated by a superposition of these initial effects, plus the requirement of equilibrium between elastic and aerodynamic forces. The superposition method can be used to solve the usual aerodynamic problems arising in longitudinal and lateral stability and control and to provide structural design criteria. Application of the method to these problems is discussed in the second part of this paper. In applying the method, once certain parameters have been calculated, the solution to a large number of specific problems follows at once by application of the superposition principle.