High-fidelity Multipoint Aerostructural Optimization of a High Aspect Ratio Tow-steered Composite Wing

Composite materials have been playing a major role in modern aircraft design due to their high stiffness and strength to weight ratio. While the advantages of composite structures over their metallic counterparts is significant, it is possible to improve even further on the benefits offered by traditional composites through the use of novel composite manufacturing methods. One such method is automated fiber placement, whereby each layer of the laminate is laid up with spatially steered fiber orientations, as opposed to the traditional method, where the fiber direction is fixed for each layer. While these new “tow-steered” composites can potentially provide additional aeroelastic tailoring when applied aircraft wing design, it is not clear how to fully take advantage of this new design freedom. To address this, we use high-fidelity gradient-based aerostructural optimization to assess the relative performance of tow-steered composites compared to conventional composites, as well as aluminum. The aircraft configuration used in this work is a high aspect ratio variant of the Common Research Model (CRM). When comparing the optimal conventional composite and optimal aluminum designs we find an improvement of roughly 8.7% in fuel burn and a 39% reduction in structural weight. The tow-steered designs yield improvements of 0.4% in fuel burn and 10% in structural weight when compared to conventional composites.