Design and manufacture of an integral twist-actuated rotor blade

Rodgers, John P.; Hagood, Nesbitt W.; Weems, Douglas

doi:10.2514/6.1997-1264

Cited by 54 publications

(32 citation statements)

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“…The blade designs of the active twist rotor used in the NASA/Army/MIT Active Twist Rotor (ATR) Program [8] and in the DARPA/Boeing/MIT Program [4] were accomplished through the exploration of several design candidates based on existing passive blades. Among the various candidates, the one with the largest static twist actuation was selected as the final design.…”

Section: Active Twist Rotorsmentioning

confidence: 99%

“…By individually controlling the twist of each blade, the local aerodynamics can be altered to obtain favorable vibration and noise reduction and possible improvement in the performance of the rotor blade. The twist actuation can be obtained by embedding active fiber composites (AFC) or macro fiber composites (MFC) [3,4] in the blade along its span to twist it or to induce warping [5]. But regardless of the technique, there is the need to optimize the material distribution along the blade in order to maximize the twist actuation.…”

Section: Introductionmentioning

confidence: 99%

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New Hybrid Optimization for Design of Active Twist Rotors

Kumar

Cesnik²

2013

54th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference

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Section: Active Twist Rotorsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

New Hybrid Optimization for Design of Active Twist Rotors

Kumar

Cesnik²

2013

54th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference

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“…Now, consider the 1/6th Mach scaled CH-47D blade ( Figure 8) built and tested at MIT (Rodgers et al, 1997). Particularly, let us consider the blade section that runs from the root to 0.54 radius as shown in Figure 8 (along with the detailed cross section layup).…”

Section: Mach-scaled Ch47-d Active Blade Sectionmentioning

confidence: 99%

Active Beam Cross-Sectional Modeling

Ortega-Morales

2001

Journal of Intelligent Material Systems and Structures

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A finite-element based analysis for modeling initially twisted and curved active composite beams with embedded anisotropic actuation is presented. It is derived from threedimensional electroelasticity, where the original problem is reduced via the variational asymptotic method. The resulting cross-sectional analysis takes into consideration passive and active anisotropic and nonhomogeneous materials, and can model general (thin-walled, thickwalled, solid, build-up structure) cross-sectional geometries. The formulation requires neither the costly use of three-dimensional finite element discretization nor the loss of accuracy inherent to any simplified representation of the cross section. The developed formulation is numerically implemented in the Active Variational-Asymptotical Beam Section Analysis code (VABS-A), and several numerical and experimental tests cases are used to support validation of the proposed theory. Also, the effect of the presence of a foam core in originally hollow configurations is presented and counter-intuitive conclusions are discussed. The generality of the method and accuracy of the results increase confidence at the design stage that the active beam structure will perform as expected and, consequently, should lower costs from experimental tests and further adjustments.

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“…By individually controlling the twist of each blade, the local aerodynamics can be altered to obtain favorable vibration and noise reduction, and possible improvement in the performance of the rotor blade. The twist actuation can be obtained by embedding active fiber composites (AFCs) or macrofiber composites [4,5] in the blade along its span to twist it. But, regardless of the technique, there is the need to optimize the material distribution along the blade in order to maximize the twist actuation.…”

Section: Introductionmentioning

confidence: 99%

“…Army/Massachusetts Institute of Technology (MIT) Active Twist Rotor (ATR) program [7] and in the Defense Advanced Research Projects Administration/Boeing Company/MIT program [5] were accomplished through the exploration of several design candidates based on existing passive blades. Among the various candidates, the one with the largest static twist actuation was selected as the final design.…”

Section: Introductionmentioning

confidence: 99%

New Optimization Strategy for Design of Active Twist Rotor

Kumar

Cesnik

2015

AIAA Journal

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This paper presents the development of a mixed-variable optimization framework for the aeroelastic analysis and design of active twist rotors. Proper tailoring of the blade properties can lead to the maximization of the active twist and the control authority for vibration reduction under operating conditions. Thus, using mathematical optimization, the cross-sectional layout is designed using continuous and discrete design variables for an active composite rotor blade to maximize the dynamic active twist while satisfying a series of constraints on blade cross-section parameters, stiffness, and strength. The optimization framework developed includes the Intelligent Cross-Section Generator as the cross-section and mesh generator, University of Michigan/Variational Asymptotic Beam Sectional analysis code for active cross-sectional analysis, and Rotorcraft Comprehensive Analysis Software for aeroelastic analysis of the active twist rotor blade. The optimization problem is solved using a surrogate-based approach in combination with the Efficient Global Optimization algorithm. In this paper, the results with mixed design variables are obtained with three different techniques and are compared with the results obtained using continuous design variables.= elastic modulus (where i is equal to 1, 2, and 3), N∕m 2 F z4 = amplitude of vertical force at the hub corresponding to 4∕rev frequency, N G ij = shear modulus, N∕m 2 M X = rolling moment at the hub in fixed frame, N · m M Y = pitching moment at the hub in fixed frame, N · m M 11 = mass per unit length, kg∕m R = blade radius, m S 44 = cross-sectional torsional stiffness, N · m 2 ε ij = cross-sectional strains θ i∕rev = amplitude of dynamic twist corresponding to i∕rev frequency (where i is equal to 3, 4, and 5), deg θ i∕rev;max = maximum amplitude of dynamic twist obtained from optimization at i∕rev actuation frequency (where i is equal to 3, 4, and 5), deg θ stat = static twist per unit length, deg ∕m θ 345∕rev = nondimensionalized amplitude of dynamic twist corresponding to 3, 4, and 5∕rev frequencies μ = advance ratio

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Design and manufacture of an integral twist-actuated rotor blade

Cited by 54 publications

References 0 publications

New Hybrid Optimization for Design of Active Twist Rotors

New Hybrid Optimization for Design of Active Twist Rotors

Active Beam Cross-Sectional Modeling

New Optimization Strategy for Design of Active Twist Rotor

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