Compliant Frame: A New Paradigm to Enable Reconfigurable Aircraft Structures

Lesieutre, George A.; Frecker, Mary; Gandhi, Farhan; Ramrakhyani, Deepak S.; Bharti, Smita; Browne, Jamie; Olympio, Raymond K.; Mehta, Vipul

doi:10.21236/ada478653

Cited by 4 publications

(3 citation statements)

References 12 publications

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“…Some efforts have been focused on the development of kinematical chains, such as the Quaternary-Binary Cross Linked Mechanism (QBCLM) (Stubbs, 2003), others on the development of compliant structures (Monner et al, 1998). Among these, the adoption of a Variable Geometry Truss (VGT) concept as primary load carrying structure is quite widespread (Baker and Friswell, 2008;Lesieutre et al, 2008;Hasse and Campanile, 2009): a VGT is a truss structural system having a number of length-adjustable members. Unfortunately all these tests remained confined to lab environments.…”

Section: Introductionmentioning

confidence: 99%

Airfoil Structural Morphing Based on S.M.A. Actuator Series: Numerical and Experimental Studies

Barbarino

Pecora

Lecce

et al. 2011

Journal of Intelligent Material Systems and Structures

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Multiple flight regimes during typical aircraft missions mean that a single unique optimized configuration, that maximizes aerodynamic efficiency and maneuverability,\ud cannot be defined. Discrete components such as ailerons and flaps provide some adaptability,\ud although they are far from optimal. Wing morphing can significantly improve the performance\ud of future aircraft, by adapting the wing shape to the specific flight regime requirements,\ud but also represents a challenging problem: the structure has to be stiff to maintain its shape\ud under loads, and yet be flexible to deform without collapse. One solution is to adopt structural\ud elements made of smart materials; Shape Memory Alloys (SMAs) have demonstrated their\ud suitability for many static applications due to their high structural integration potential and\ud remarkable actuation capabilities.\ud In this work, the airfoil camber at the wing trailing edge on a full scale wing of a civil\ud regional transportation aircraft is controlled by substituting a traditional split flap with a\ud hingeless, smooth morphed flap. Firstly, the development and testing of an actuator device\ud based on a SMA ribbon, capable of a net rotation of 5 deg, is presented. Then, a flap bay is\ud designed and experimentally tested in presence of static loads, based on a compliant rib built\ud as a series repetition of the proposed actuator. An aero-thermo-mechanical simulation within\ud a FE approach was adopted to estimate the behavior and performance of the compliant rib,\ud integrating both aerodynamic loads, by means of a Vortex Lattice Method (VLM) code, and\ud SMA phenomenology, implementing Liang and Rogers’ constitutive model. The prototype\ud showed good actuation performance even in presence of external loads. Very good numerical\ud experimental correlation is found for the unloaded case, while some fatigue issues emerged\ud in presence of static load

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Section: Introductionmentioning

confidence: 99%

Airfoil Structural Morphing Based on S.M.A. Actuator Series: Numerical and Experimental Studies

Barbarino

Pecora

Lecce

et al. 2011

Journal of Intelligent Material Systems and Structures

View full text Add to dashboard Cite

show abstract

“…Between the different classes of morphing wing designs, one can list the planform alteration concept (span, chord, and sweep changes), the out-of-plane airframe transformation (twist, and span-wise bending), and the airfoil adjustment (camber and thickness) [1][2][3]. Morphing wing designs have been proposed and evaluated by several research groups, industries and within national/international programmes, like the NASA/ DAPPA/AFRL/Next-Gen Inc., FlexSys Inc., teams at Virginia Tech, Universities of Florida, Bristol and Swansea [1][2][3][4][5][6][7][8][9][10][11][12]. Morphing wings are complex and sophisticated systems, which consist of shape-changing skins, actuators, wing substructures and associated mechanisms [2,3].…”

Section: Introductionmentioning

confidence: 99%

Variable stiffness corrugated composite structure with shape memory polymer for morphing skin applications

Gong¹,

Liu²,

Scarpa³

et al. 2017

Smart Mater. Struct.

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This work presents a variable stiffness corrugated structure based on a Shape Memory Polymer (SMP) composite with corrugated laminates as reinforcement that shows smooth aerodynamic surface, extreme mechanical anisotropy and variable stiffness for potential morphing skin applications. The smart composite corrugated structure shows a low in-plane stiffness to minimize the actuation energy, but also possess high out-of-plane stiffness to transfer the aerodynamic pressure load. The skin provides an external smooth aerodynamic surface because of the one-sided filling with the SMP. Due to variable stiffness of the shape memory polymer the morphing skin exhibits a variable stiffness with a change of temperature, which can help the skin adjust its stiffness according different service environments and also lock the temporary shape without external force. Analytical models related to the transverse and bending stiffness are derived and validated using Finite Element techniques. The stiffness of the morphing skin is further investigated by performing a parametric analysis against the geometry of the corrugation and various sets of SMP fillers. The theoretical and numerical models show a good agreement and demonstrate the potential of this morphing skin concept for morphing aircraft applications. We also perform a feasibility study of the use of this morphing skin in a variable camber morphing wing baseline. The results show that the morphing skin concept exhibits sufficient bending stiffness to withstand the aerodynamic load at low speed (less than 0.3 Ma), while demonstrating a large transverse stiffness variation (up to 191 times) that helps to create a maximum mechanical efficiency of the structure under varying external conditions.

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“…Some efforts have been spent on the development of kinematical chains (Stubbs, 2003), and others on the development of compliant structures (Monner et al, 1998). Among these, the adoption of a Variable Geometry Truss concept as primary load-carrying structure is quite widespread (Baker and Friswell, 2008;Lesieutre et al, 2008;Hasse and Campanile, 2009). It is within this vibrant scientific framework that motivations were found to address a challenging study oriented to preliminarily investigate the structural feasibility of a variable-camber trailing-edge architecture specifically conceived for a large civil transportation aircraft.…”

Section: Introductionmentioning

confidence: 99%

Design and Functional Test of a Morphing High-Lift Device for a Regional Aircraft

Pecora

Barbarino

Concilio

et al. 2011

Journal of Intelligent Material Systems and Structures

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Several flight regimes occurring during a typical aircraft mission make it impossible to define a unique optimized wing configuration able to maximize aerodynamic efficiency,\ud maneuverability, and stability in every flight condition. Components like ailerons and flaps, in some way, guarantee a certain level of adaptability, being far from optimal.\ud Wing morphing can strongly improve the aerodynamic efficiency of future aircraft by assuring an optimal adaptive behavior which best fits the specific flight regime requirements. Such an approach, in spite of related benefits, presents a challenging problem: the same structure rigid enough to keep its shape under the aerodynamic loads has to largely deform itself without\ud undergoing structural collapses. In the frame of a research project funded by Alenia Aeronautica S.p.A., the authors came to the definition of a novel morphing architecture\ud acting as high-lift device.\ud In this study, the design assessment of an innovative flap architecture for a variable-camber trailing edge is illustrated. The reference geometry is based on a full-scale wing of a reference civil regional transportation aircraft, where the conventional flap component has been substituted by a morphing trailing edge based on compliant ribs. The presented architecture moves toward the direction of assuring high deformability while keeping good load-sustaining capabilities: each rib is composed of multiple, suitably shaped rigid elements connected by\ud means of hinges and linking rods. The rib’s shape changes upon the activation of a smart actuator based on shape memory alloy technology. Design process of the morphing rib and integrated actuator structure has been widely discussed as well as the functional tests performed\ud on a technological demonstrator manufactured in order to prove the goodness of chosen design strategies and adopted numerical models

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Compliant Frame: A New Paradigm to Enable Reconfigurable Aircraft Structures

Cited by 4 publications

References 12 publications

Airfoil Structural Morphing Based on S.M.A. Actuator Series: Numerical and Experimental Studies

Airfoil Structural Morphing Based on S.M.A. Actuator Series: Numerical and Experimental Studies

Variable stiffness corrugated composite structure with shape memory polymer for morphing skin applications

Design and Functional Test of a Morphing High-Lift Device for a Regional Aircraft

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