Aeroelastic design and optimization of strut-braced high aspect ratio wings

Aeroelastic design and optimization of strut-braced high aspect ratio wings

Toffol Francesco, Sergio Ricci

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Abstract. To improve aircraft aerodynamic efficiency, a possible solution is to increase the wing aspect ratio to reduce the induced drag term. As a drawback, the span increase introduces an increment of the wing loads, specially of the wing root bending moment that drives the sizing of the wing. Structural mass must be added to withstand higher loads, reducing the aerodynamic advantage from a fuel consumption point of view, as it can be instinctively seen in the Breguet’s range equation. To limit the load increment due to the increased span, a possible solution is the usage of a strut: this kind of structure modifies the load path spanwise, diminishing the wing internal forces and reducing the wing penalty mass. In this framework, a lot of research is done studying Ultra-High Aspect Ratio Strut-Braced Wing, where the aspect ratio of such configuration is exasperated above 15, and the resulting wing is extremely flexible and may experience large deformation under loading. Moreover, the over determined structure realized by the fuselage-wing-strut connections deserves particular attention to fully characterize the aeroelastic interaction among the structural elements. For this reason, a two-step design approach that exploits NeoCASS (GUESS + NeOPT) is used to provide a sizing of the wing and of the strut considering several structural and aeroelastic constraints (e.g. flutter and ailerons effectiveness).

Strut-Braced Wing, High Aspect Ratio Wing, Conceptual Design

Published online 11/1/2023, 6 pages
Copyright © 2023 by the author(s)
Published under license by Materials Research Forum LLC., Millersville PA, USA

Citation: Toffol Francesco, Sergio Ricci, Aeroelastic design and optimization of strut-braced high aspect ratio wings, Materials Research Proceedings, Vol. 37, pp 42-47, 2023


The article was published as article 10 of the book Aeronautics and Astronautics

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[1] Gur, O.; Bhatia, M.; Schetz, J.A.; Mason, W.H.; Kapania, R.K.; Mavris, D.N. Design Optimization of a Truss-Braced-Wing Transonic Transport Aircraft. J. Aircr. 2010, 47, 1907–1917.
[2] Bradley, M.K.; Droney, C.K.; Allen, T.J. Subsonic Ultra-Green Aircraft Research (No. NF1676L-19776). Available online: (accessed on 19 January 2023).
[3] Hosseini, S.; Ali Vaziri-Zanjani, M.; Reza Ovesy, H. Conceptual Design and Analysis of an Affordable Truss-Braced Wing Regional Jet Aircraft. Proc. Inst. Mech. Eng. Part G: J. Aerosp. Eng. 2020.
[4] Harrison, N.A.; Gatlin, G.M.; Viken, S.A.; Beyar, M.; Dickey, E.D.; Hoffman, K.; Reichenbach, E.Y. Development of an Efficient m= 0.80 Transonic Truss-Braced Wing Aircraft. In Proceedings of the AIAA Scitech 2020 Forum, Orlando, FL, USA, 6 January–10 January 2020.
[5] Ricci, S., Paletta, N., Defoort, S., Benard, E., Cooper, J. E., & Barabinot, P. (2022). U-HARWARD: a CS2 EU funded project aiming at the Design of Ultra High Aspect Ratio Wings Aircraft. In AIAA Scitech 2022 Forum (p. 0168).
[6] D. Raymer, Aircraft design: a conceptual approach. American Institute of Aeronautics and Astronautics, Inc., 2012.
[7] E. Torenbeek, Synthesis of subsonic airplane design: an introduction to the preliminary design of subsonic general aviation and transport aircraft, with emphasis on layout, aerodynamic design, propulsion and performance. Springer Science & Business Media, 2013.
[8] L. Cavagna, S. Ricci, and L. Travaglini, “Neocass: an integrated tool for structural sizing, aeroelastic analysis and mdo at conceptual design level,” Progress in Aerospace Sciences, vol. 47, no. 8, pp. 621–635, 2011.
[9] L. Cavagna, S. Ricci, and L. Travaglini, “Structural sizing and aeroelastic optimization in aircraft conceptual design using neocass suite,” in 13th AIAA/ISSMO Multidisciplinary Analysis Optimization Conference, p. 9076, 2010.
[10] L. Cavagna, S. Ricci, and L. Riccobene, “A fast tool for structural sizing, aeroelastic analysis and optimization in aircraft conceptual design,” in 50th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference 17th AIAA/ASME/AHS Adaptive Structures Conference 11th AIAA No, p. 2571, 2009.
[11] L. Cavagna, S. Ricci, and L. Riccobene, “Structural sizing, aeroelastic analysis, and optimization in aircraft conceptual design,” Journal of Aircraft, vol. 48, no. 6, pp. 1840–1855, 2011.
[12] Fonte, F., & Ricci, S. (2019). Recent developments of NeoCASS the open source suite for structural sizing and aeroelastic analysis. In 18th International Forum on Aeroelasticity and Structural Dynamics (IFASD 2019) (pp. 1-22)
[13] Toffol, F., & Ricci, S. (2023). A Meta-Model for composite wingbox sizing in aircraft conceptual design. Composite Structures, 306, 116557.
[14] Toffol, F., & Ricci, S. (2023). Preliminary Aero-Elastic Optimization of a Twin-Aisle Long-Haul Aircraft with Increased Aspect Ratio. Aerospace, 10(4), 374.
[15] Toffol, F. (2021). Aero-servo-elastic optimization in conceptual and preliminary design.
[16] EASA Easy Access Rules for Large Aeroplanes. Available online: (accessed on 19 January 2023).
[17] Carrier, G. G., Arnoult, G., Fabbiane, N., Schotte, J. S., David, C., Defoort, S., … & Delavenne, M. (2022). Multidisciplinary analysis and design of strut-braced wing concept for medium range aircraft. In AIAA SCITECH 2022 Forum (p. 0726).