Variable Stiffness Spar Wind-Tunnel Model Development and Testing

Florance, James R.; Heeg, Jennifer; Spain, C. Victor; Ivanco, Thomas G.; Wieseman, Carol D.; Lively, Peter S.

doi:10.2514/6.2004-1588

Cited by 19 publications

(15 citation statements)

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“…The DARPA/AFRL/NASA/Northrop Grumman Smart Wing program [2] became the most famous one by realizing hingeless smart control of the curved surface of airfoil structure with SMA, the results of which showed that improvements in rolling moment and overall pressure distributions were achieved as compared to a conventional aileron [3][4][5]. Yousefi-Koma and Zimcik [6], Nam et al [7] and Florance et al [8] have assembled a Variable Stiffness Spar inside a wing to realize the changeability of stiffness to improve aerodynamic quality.…”

Section: Introductionmentioning

confidence: 99%

A changeable aerofoil actuated by shape memory alloy springs

Dong

Zhang

Liang

2008

Materials Science and Engineering: A

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Section: Introductionmentioning

confidence: 99%

A changeable aerofoil actuated by shape memory alloy springs

Dong

Zhang

Liang

2008

Materials Science and Engineering: A

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“…Nam et al demonstrated that the torsion-free wing can provide significant aeroelastic amplification, leading to an increase in roll-rate between 8% and 48% over the baseline performance in the worst possible flight conditions. Florance et al (8) investigated the use of the VSS concept to exploit the wing flexibility and to improve the aerodynamic performance of the vehicle. Their wing incorporated a spar with a rectangular cross-section that runs from the wing root up to 58% of the overall wing semi-span.…”

Section: Introductionmentioning

confidence: 99%

Roll control of a MALE UAV using the adaptive torsion wing

Ajaj¹,

Friswell

Dettmer

et al. 2013

Aeronaut. j. (1968)

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This paper assesses the feasibility of the Adaptive Torsion Wing (ATW) concept to replace conventional ailerons and enhance the manoeuvrability of a MALE UAV. The ATW concept is a thin-walled closed section two-spar wingbox whose torsional stiffness can be adjusted through the chord-wise position of the front and rear spar webs. The reduction in torsional stiffness allows external aerodynamic loads to induce aeroelastic twist that can be used as a function of the flight conditions to obtain a desired roll control authority. Modelling of the concept was performed using a conceptual design tool developed in MATLABTM. The variation of structural figures of merit are evaluated and discussed. Finally, an MDO study was performed to have in-depth assessments of the potential benefits of the ATW in replacing ailerons and providing sufficient roll control.

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“…Nam et al demonstrated that the torsion-free wing can provide significant aeroelastic amplification, leading to an increase in roll-rate between 8% and 48 % over the baseline performance in the worst possible flight conditions. Florance et al (11) investigated the use of the VSS concept to exploit the wing flexibility and to improve the aerodynamic performance of the vehicle. Their wing incorporated a spar with a rectangular cross-section that runs from the wing root up to 58% of the overall wing semi-span.…”

Section: Introductionmentioning

confidence: 99%

Performance and control optimisations using the adaptive torsion wing

Ajaj¹,

Friswell

Dettmer

et al. 2012

Aeronaut. j. (1968)

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This paper presents the Adaptive Torsion Wing (ATW) concept and performs two multidisciplinary design optimisation (MDO) studies by employing this novel concept across the wing of a representative UAV. The ATW concept varies the torsional stiffness of a two-spar wingbox by changing the enclosed area through the relative chordwise positions of the front and rear spar webs. The first study investigates the use of the ATW concept to improve the aerodynamic efficiency (lift-to-drag ratio) of the UAV. In contrast, the second study investigates the use of the concept to replace conventional ailerons and provide roll control. In both studies, the semi-span of the wing is split into five equal partitions and the concept is employed in each of them. The partitions are connected through thick ribs that allow the spar webs of each partition to translate independently of the webs of adjacent partitions and maintain a continuous load path across the wing span. An MDO suite consisting of a Genetic Algorithm (GA) optimiser coupled with a high-end low-fidelity aero-structural model was developed and employed in this paper.

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Variable Stiffness Spar Wind-Tunnel Model Development and Testing

Cited by 19 publications

References 0 publications

A changeable aerofoil actuated by shape memory alloy springs

A changeable aerofoil actuated by shape memory alloy springs

Roll control of a MALE UAV using the adaptive torsion wing

Performance and control optimisations using the adaptive torsion wing

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