Large Deformation Modeling of a Beam Type Structure and a 3D Wingbox using an Enhanced Modal Approach

Kurzfassung

A recently developed modal-based method that captures the geometric nonlinear ef- fects that arise in the regime of large deformations of wing-like structures is applied to the modeling of a highly flexible beam structure and a 3D wingbox configuration. The method features quadratic and cubic stiffness terms and calculates the nodal deformation field not only by normal modes but also by additional mode components up to fourth or- der. Thus, both a nonlinear force-displacement relationship and a geometrically nonlinear displacement field are accounted for. Static and dynamic results for the two configurations are presented together with results from a commercial finite element solver and from the UM/NAST aeroelastic solver from the University of Michigan. The numerical study high- lights the capability of the method to capture the nonlinear effects and demonstrates its power to model a 3D wingbox structure made of shell elements with anisotropic material characteristics.