Rib Spacing Optimization of a Generic UAV Wing to Increase the Aeroelastic Endurance

Design and usage of Unmanned Aerial Vehicles (UAV) especially for military purposes has been rapidly increasing in recent years due to their capability to endure long flight durations without needing a crew and due to their low cost compared with the conventional military aircrafts. In order to increase range and flight time endurance of a UAV, aspect ratio of the wing should be increased. This increment leads to aeroelastic problems such as flutter if the cruise velocity is high enough. On the other hand, the flutter velocity of the wing is strictly depending on the ratios of first body bending and torsional frequency values. In order to shift the flutter velocity to higher values, ratio of the torsional frequency to the first body bending frequency of the wing should be increased. Therefore, within the content of this research it is aimed to optimize the wing rib spacing of a generic UAV to maximize the wing frequency ratio. Parametric wing model will be constructed and modal analysis will be performed in Abaqus finite element commercial software environment with the assistance of a Python script and optimization process will be carried by Mode Frontier optimization software. Finally, the optimum rib spacing will be determined for the wing structure.