Aeroelastic Topology Optimization of Blade-Stiffened Panels

Metallic blade-stiffened panels are optimized for various eigenvalue metrics of interest to the aerospace community. This is done via solid isotropic material with penalization-based topology optimization: the stiffeners are discretized into finite elements, and each element is assigned a design variable, which may vary from 0 (void) to 1 (solid). A known issue with eigenvalue-based optimization is discontinuities due to mode switching, which may be avoided through a series of eigenvalue separation constraints, or (more challenging, but less restrictive) a bound method with mode tracking. Both methods are demonstrated to obtain optimal stiffener topologies for panel buckling, but only the former is used for aeroelastic panel-flutter problems. Satisfactory flutter optimal results are obtained, but the work concludes with a discussion of the challenges associated with the use of a bound method for aeroelastic problems, with specific complications posed by the advent of hump modes.