Nonlinear Negative Stiffness Wingtip Spring Device for Gust Loads Alleviation

Castrichini, Andrea; Cooper, Jonathan E.; Wilson, Thomas; Carrella, A.; Lemmens, Yves

doi:10.2514/1.c033887

Cited by 39 publications

(31 citation statements)

References 14 publications

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“…Therefore, this contrasting stiffness requirement for trimmed-flight and gust loads alleviation has led to proposed solutions such as bi-stable wing-tips 4 and active control via piezoelectric actuators 5 . Despite this complication, the folding wing-tip concept remains promising as recent research have suggested that coupling the folding wing-tip to a nonlinear spring system may provide the solution 6,7 .…”

Section: Introductionmentioning

confidence: 99%

Modelling of Folding Wing-Tip Devices for Gust Loads Alleviation

Cheung¹,

Wales²,

Rezgui³

et al. 2018

2018 AIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference

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High aspect ratio wings have been the focus of recent aircraft designs for improved fuel consumption through reducing induced drag. The increase in wing span has also led to folding wing-tips being introduced as a solution for meeting airport gate requirements. Recent studies have suggested such a folding wing-tip solution may be incorporated with spring devices in order to provide an additional gust loads alleviation ability in flight. The current work examines the suitability of using the Doublet-Lattice Method and the Unsteady Vortex-Lattice Method for modelling the dynamic response of such a folding wing-tip device and found that the Doublet-Lattice Method tends to over-predict the achievable gust loads alleviation because it cannot fully capture the coupling between folding and the change in local angle of attack of the wing-tip. Additional analysis also found that when using the Unsteady Vortex-Lattice Method, choosing large displacement method over linear method for solving the structural response only produced minimal difference.

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Section: Introductionmentioning

confidence: 99%

Modelling of Folding Wing-Tip Devices for Gust Loads Alleviation

Cheung¹,

Wales²,

Rezgui³

et al. 2018

2018 AIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference

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show abstract

“…This differing optimal stiffness for trimmed-flight and gust loads alleviation has led to proposed solutions such as bi-stable wing-tips [17] and active control via piezoelectric actuators [18]. Despite this complication, the folding wing-tip concept remains promising as recent research have suggested that coupling the folding wing-tip to a nonlinear spring system may provide the solution [19,20].…”

mentioning

confidence: 99%

Testing of a Hinged Wingtip Device for Gust Loads Alleviation

Cheung

Rezgui

Cooper

et al. 2018

Journal of Aircraft

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Recent aircraft designs have considered higher aspect ratio wings to reduce induced drag for improved fuel efficiency; however, to remain compliant with airport gate requirements, folding wing-tips have been introduced as a solution to the increased wingspan. Recent numerical studies suggest that a folding wing-tip solution may be incorporated with spring devices to provide an additional gust loads alleviation ability in flight as well. In this work, a series of low-speed steady and dynamic wind tunnel tests was conducted using a prototype of such a concept. It was found that a folding wing-tip with a non-zero relative angle of the folding hinge axis to the stream-wise direction could provide gust loads alleviation. The level of load alleviation varied with hinge spring stiffness and lifting condition, with the best performance achieving a 56% reduction in peak loading.

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“…This differing optimal stiffness for trimmed-flight and gust loads alleviation has led to proposed solutions such as bi-stable wing-tips 15 and active control via piezoelectric actuators 16 . Despite this complication, the folding wing-tip concept remains promising as recent research have suggested that coupling the folding wing-tip to a nonlinear spring system may provide the solution 17,18 . The work described in this paper aims to obtain baseline experimental data of the folding wing-tip concept when coupled with a linear spring device, particularly focusing on the effect of a non-zero hinge angle has on the its gust loads alleviation performance through low-speed wind tunnel testing.…”

Section: F 2 American Institute Of Aeronautics and Astronauticsmentioning

confidence: 99%

Testing of Wing-Tip Spring Device for Gust Loads Alleviation

Cheung¹,

Castrichini²,

Rezgui³

et al. 2017

58th AIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference

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General rightsThis document is made available in accordance with publisher policies. Please cite only the published version using the reference above. Full terms of use are available: http://www.bristol.ac.uk/pure/about/ebr-terms Recent aircraft designs have begun considering higher aspect ratio wings to reduce induced drag for improved fuel efficiency. In order to meet airport gate requirements, folding wing-tips have been introduced as a solution to the increased wing-span. Recent numerical studies have suggested such a folding wing-tip solution may be incorporated with spring devices in order to provide an additional gust loads alleviation ability in flight. A series of lowspeed wind tunnel tests was conducted using a prototype of such a concept and found that a folding wing-tip with a non-zero relative angle of the folding hinge axis to the stream-wise direction can provide gust loads alleviation. It was also concluded that the weight of the wingtip may have a strong influence on the hinge stiffness necessary for best performance. The findings from these tests agree with previous simulations in a qualitative manner.

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Nonlinear Negative Stiffness Wingtip Spring Device for Gust Loads Alleviation

Cited by 39 publications

References 14 publications

Modelling of Folding Wing-Tip Devices for Gust Loads Alleviation

Modelling of Folding Wing-Tip Devices for Gust Loads Alleviation

Testing of a Hinged Wingtip Device for Gust Loads Alleviation

Testing of Wing-Tip Spring Device for Gust Loads Alleviation

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