Nonlinear Structural, Nonlinear Aerodynamic Model for Static Aeroelastic Problems

摘要

The paper presents the derivation of a modal nonlinear structural model and its coupling with a nonlinear aerodynamic model for static aeroelastic analysis of highly deformable configurations. The structural analysis, intended for geometrically nonlinear structures, computes the deformations of a beamlike structure by dividing it into a few segments. Large deformations are treated as the sum of large, rigid-body displacements of the segment plus small, elastic deformation within the segment. The latter are computed using a modal approach, where the natural modes of each segment are calculated with augmented large fictitious masses to improve the coupling between segments. The use of a modal method in a large-deformation case introduces difficulties in the application of compatibility equations, which are explained and addressed in the paper. The nonlinear aerodynamic model is an equivalent strip theory, in which each section is assigned a database of aerodynamic coefficients. Both the aerodynamic and structural models are suitable for beam-like wing structures and are highly computationally efficient. The numerical examples include three loading cases that validate the implementation of the methodology and demonstrate its use for static aeroelastic applications.