Nonlinear aeroelastic analysis of highly flexible wings using the modal rotation method

The paper presents a nonlinear, aeroelastic framework for the analysis of highly flexible wings accounting for large deformations, using a linear modal database. A nonlinear static analysis is conducted followed by a flutter analysis of the deformed shape. The wing deformations are computed with the recently presented Modal Rotation Method (MRM) that computes large structural deformations using spatial derivatives of the mode shapes defined as curvature modes. The MRM is coupled with an aerodynamic model, based on the rigid configuration, to compute static aeroelastic deformations. The method was extended to compute mode-shapes and frequencies of the deformed structure and to alter the unsteady aerodynamic matrices, to obtain a flutter solution of the deformed wing. Results were validated based on two experimental studies from the literature.