Design, analyses, and model tests of an aeroelastically tailored lifting surface

Rogers, William A.; Braymen, W.W.; Shirk, M. H.

doi:10.2514/6.1981-1673

Cited by 4 publications

(2 citation statements)

References 8 publications

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“…Taking the variation of the time integral of the Lagrangian L, the mass and stiffness matrices of the T18 element can readily be found to be (8) (9)…”

Section: T = Y2b?p S T S (2a)iq} T [Q] T [A][q]{q}mentioning

confidence: 99%

“…Lottati discovered that the effect of bending-torsion stiffness coupling makes a compromise between flutter and divergence characteristics for various sweep angles. For plate-like wings, Rogers et al 8 and Braymen et al 9 performed work in the aeroelastically tailored lifting surfaces concerned mainly with static aerodynamic improvements. In spite of their efforts, the amount of analytical and experimental investigations put forward for flutter characteristics of plate-like composite wings has been very limited.…”

Section: Introductionmentioning

confidence: 99%

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Flutter analysis of cantilever composite plates in subsonic flow

Lin

Tarn

1989

AIAA Journal

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The high-precision 18-degree-of-freedom triangular plate-bending finite element is used to study the effects of composite filament angle, orthotropic modulus ratio, sweep angle, and aspect ratio on the vibration and flutter/divergence characteristics of cantilever plates in subsonic flow. The element stiffness and mass matrices are generated according to the classical lamination theory. Unsteady airload acting on the plate is evaluated by the use of lifting surface theory, which is solved numerically by the doublet-lattice method. To facilitate flutter analysis, interpolation using a surface spline is employed to interconnect the structural nodal and aerodynamic control points. The flutter/divergence tradeoff of aeroelastic tailoring is found, in a more involved manner, for the present plate-like low-aspect-ratio wings as compared to that associated with the beam model first discovered by Weisshaar. Effective enhancement on flutter/divergence performance can be attained by varying the orthotropic modulus ratio while as appropriate fiber orientation is selected. Also, as discovered previously, the present numerical results confirm that the structural tailoring can provide a harmonious balance to the sweep angle effect upon the aeroelastic stability characteristics of a wing. From the numerical examinations performed, it is concluded that substantial improvement upon flutter/divergence characteristics can be achieved by using composite materials. Nevertheless, the benefit can be gained only through a thorough parametric investigation because the aeroelastic stabilities are also complicated by the directional stiffness of composites, in particular for the cases of low-aspect-ratio wings.

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“…Taking the variation of the time integral of the Lagrangian L, the mass and stiffness matrices of the T18 element can readily be found to be (8) (9)…”

Section: T = Y2b?p S T S (2a)iq} T [Q] T [A][q]{q}mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Flutter analysis of cantilever composite plates in subsonic flow

Lin

Tarn

1989

AIAA Journal

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Aeroelastic tailoring in vehicle design synthesis

Love

Bohlmann

1991

32nd Structures, Structural Dynamics, and Materials Conference

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Aeroelastic tailoring for improved UAV performance

Weisshaar

Nam

Batista-Rodriguez

1998

39th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference and Exhibit

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This paper describes how aeroelastic tailoring, in concert with optimal composite material design, might be applied to a new generation of Unmanned Air Vehicles (UAV's) to increase range and improve lateral control effectiveness. UAV development provides a new venue for design because it encourages creativity by removing some design constraints. This paper reviews: 1) design opportunities provided by UAV missions; 2) and, aeroelastic tailoring features mat lend themselves to improved performance. The aeroelastic features discussed in this paper are: lateral control and, reduced induced drag. Our studies show that aeroelastic tailoring can increase the control reversal speed of swept wings and that different laminate designs are needed depending on whether leading edge or trailing edge controls are used. We also show that induced drag can be controlled by laminate tailoring and that in some cases drag can be reduced if the wing structural aspect ratio is low, about AR=3. PurposeUnmanned Air Vehicle (UAV) development has been identified as a future development area with potentially revolutionary outcomes. 1 Two highlighted areas for UAV's with special technological challenges are vehicles to suppress air defenses and improved high altitude observation and weapon carrying aircraft.The purposes of this paper are to • describe design opportunities provided by UAV missions and the need for increased performance• summarize the effects of controlled aeroelastic interaction with advanced composite aircraft wings that aeroelastically couple structural flexibility and wing control surfaces to improve airplane maneuverability and reduce induced drag. UAV benefits and attributesTechnological capability always runs far ahead of application to real aircraft because of the need to thoroughly consider the trade between system performance benefits from the technology and the cost of the technology. As a result, some technology can languish for years before it sees an application to a real air vehicle. Today we have few opportunities to test new technology on real flight vehicles; this situation is unlikely to change in the future. This means that worthwhile technology will take a long time to mature. On the other hand, UAV's offer low cost vehicles that can benefit from new technology.UAV literature (and that of their predecessors, the Remotely Piloted Vehicles or RPV's) is extensiveê xtending over the past few decades. 5 " It is not our purpose to review the history of UAV or RPV development since UAV's and RPV's have a long history; numerous regularly scheduled conferences have been held world-wide during the past few decades. Basic technology for RPV's is well-developed and manufacturers world-wide offer a variety of products.On the other hand, recent interest in military UAV's triggered by advances in computer information technology and navigation has opened up new possibilities.A review of the recent literature reveals many claimed UAV benefits. These include:1. Reduced human risk with increased capability for dangerous missi...

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Design, analyses, and model tests of an aeroelastically tailored lifting surface

Cited by 4 publications

References 8 publications

Flutter analysis of cantilever composite plates in subsonic flow

Flutter analysis of cantilever composite plates in subsonic flow

Aeroelastic tailoring in vehicle design synthesis

Aeroelastic tailoring for improved UAV performance

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