The effect of stiffness and geometric parameters on the nonlinear aeroelastic performance of high aspect ratio wings

F. Afonso, G. Leal, J. Vale, Oliveira, F. Lau, A. Suleman

Research output: Contribution to journalArticle

3 Citations (Scopus)


The increase in wing aspect ratio is gaining interest among aircraft designers in conventional and joined-wing configurations due to the higher lift-to-drag ratios and longer ranges. However, current transport aircraft have relatively small aspect ratios due their increased structural stiffness. The more flexible the wing is more prone to higher deflections under the same operating condition, which may result in a geometrical nonlinear behavior. This nonlinear effect can lead to the occurrence of aeroelastic instabilities such as flutter sooner than in an equivalent stiffer wing. In this work, the effect of important stiffness (inertia ratio and torsional stiffness) and geometric (sweep and dihedral angles) design parameters on aeroelastic performance of a rectangular high aspect ratio wing model is assessed. The torsional stiffness was observed to present a higher influence on the flutter speed than the inertia ratio. Here, the decrease of the inertia ratio and the increase of the torsional stiffness results in higher flutter and divergence speeds. With respect to the geometric parameters, it was observed that neither the sweep angle nor the dihedral angle variations caused a substantial influence on the flutter speed, which is mainly supported by the resulting smaller variations in torsion and bending stiffness due to the geometric changes.

Original languageEnglish
Pages (from-to)1824-1850
Number of pages27
JournalProceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering
Issue number10
Early online date25 Nov 2016
Publication statusPublished - 1 Aug 2017


  • fluid-structure interaction
  • flutter boundary prediction
  • high aspect ratio wings
  • nonlinear aeroelasticity

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