Design Optimization of Flexible Aircraft Wings Using Tow-Steered Composites
Aerospace Engineering PhD Candidate: Tim Brooks, Dissertation Chair: Professor Joaquim Martins

Automatic fiber placement machines have made it viable to manufacture composites where fiber angles vary spatially throughout each layer of the laminate---tow-steered composites. This additional design freedom provided by tow-steered composites have the potential to increase their structural performance relative to their conventional uniaxial fiber counterparts. One area of interest for application of these composites is in the design of flexible wing structures.

High-fidelity aerostructural solvers have been proven effective for accurately capturing the trade-offs between relevant design disciplines for such aircraft. By complementing these solvers with gradient-based numerical optimization, the maximum benefits offered by tow-steered structures can be quantified.

In this thesis, several optimization studies are conducted to compare the performance of conventional and tow-steered composite wings. When minimizing the fuel burn of a Boeing-777-type aircraft, tow steering is found to offer up to 2.3% in fuel savings relative to an optimized conventional composite wing. The trade-off between structural weight and fuel burn performance is then explored through a Pareto front study. In this study, it is found that when wing planform is free to vary, tow-steering offers improvements of up to 1.5% and 1.6% in aircraft fuel burn and structural weight, respectively, depending on the design objective.


Dissertation Committee Names:
Chair: Prof. Joaquim R. R. A. Martins
Cognate Member: Prof. Kazuhiro Saitou
Members: Prof. Carlos E. S. Cesnik and Prof. Veera Sundararaghavan

Publications

Journal Publications
T. R. Brooks, G. K. W. Kenway, and J. R. R. A. Martins, “uCRM: An Aerostructural Model for the Study of Flexible Transonic Aircraft Wings”, AIAA Journal, 2018.

T. R. Brooks and J. R. R. A. Martins, “On Manufacturing Constraints for Tow-steered Composite Design Optimization”, Composite Structures, 2018 (submitted).

Conference Proceedings
T. R. Brooks, G. K. W. Kenway, and J. R. R. A. Martins, “Undeflected Common Research Model (uCRM): An Aerostructural Model for the Study of High Aspect Ratio Transport Aircraft Wings,” in 18th AIAA/ISSMO Multidisciplinary Analysis and Optimization Conference, 2017.

T. R. Brooks, G. J. Kennedy, and J. R. R. A. Martins, “High-fidelity Multipoint Aerostructural Optimization of a High Aspect Ratio Tow-steered Composite Wing,” in 58th AIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, 2017.

T. R. Brooks, G. J. Kennedy, and J. R. R. A. Martins, “High-fidelity Aerostructural Optimization of a High Aspect Ratio Tow-steered Wing,” in 58th AIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, 2016.

T. R. Brooks, J. T. Hwang, G. J. Kennedy, and J. R. R. A. Martins, “High-fidelity Structural Optimization of a Tow-Steered Composite Wing,” in 11th World Congress on Structural and Multidisciplinary Optimization, 2015.