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

Abstract

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