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Dynamic modelling and stability of hingeless helicopter blades with a smart spring

Published online by Cambridge University Press:  03 February 2016

F. F. Afagh ,
F. Nitzsche  and
N. Morozova
F. F. Afagh
Affiliation:
Department of Mechanical and Aerospace Engineering, Carleton University, Ottawa, Canada
F. Nitzsche
Affiliation:
Department of Mechanical and Aerospace Engineering, Carleton University, Ottawa, Canada
N. Morozova
Affiliation:
Department of Mechanical and Aerospace Engineering, Carleton University, Ottawa, Canada
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Abstract

The aeroelastic stability of a uniform, untwisted hingeless ‘smart’ helicopter rotor blade in hover has been analysed. The concept of a ‘smart’ blade is achieved by implementing a piezoelectric stack at an appropriate location along a host blade such that upon actuation it enters the load path becoming an integral part of the host structure. Thus, the stiffness characteristics of the rotor are altered causing modal damping augmentation of the blade. The perturbation equations of motion for the ‘smart’ blade that describe the unsteady blade motion about the equilibrium operating condition are obtained using Galerkin’s method. These differential equations with periodic time coefficients are analysed for stability utilising the Floquet method. Six different regimes of actuation are investigated, and a parametric study is carried out by considering six different design cases. It is shown that, compared to a ‘host’ blade the stability characteristics of the ‘smart’ blade are not affected adversely. In fact, a judicious design and actuation of the ‘smart’ spring has the potential of improving the stability boundaries of individual blades.

Type
Research Article
Information
The Aeronautical Journal , Volume 108 , Issue 1085 , July 2004 , pp. 369 - 377
Copyright
Copyright © Royal Aeronautical Society 2004 

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References

1. Chopra, I. and McCloud, J.L. A numerical simulation study of open-loop, closed-loop and adaptive multicycle control systems, J Amer Heli Soc, 1983, 28, (1), pp 63–77.Google Scholar
2. Jacob, H.G. and Lehmann, G. Optimization of blade pitch angle for higher harmonic rotor control, Vertica, 1983, 7, (3), pp 271–286.Google Scholar
3. Hammon, C.E. Wind tunnel results showing rotor vibration loads reduction using higher harmonic blade pitch, J Amer Heli Soc, 1983, 28, (1), pp 10–15.Google Scholar
4. Molusis, J.A., Hammond, C.E. and Cline, J.H. A unified approach to the optimal design of adaptive and gain scheduled controllers to achieve minimum helicopter vibration, J Amer Heli Soc, 1983, 28, (2), pp 9–18.Google Scholar
5. Wood, E.R., Powers, R., Cline, J.H. and Hammond, C.E. On developing and flight testing a higher harmonic control system, J Amer Heli Soc, 1985, 30, (1), pp 3–20.Google Scholar
6. Lehmann, G. The effect of higher harmonic control (HHC) on a four-bladed hingeless model rotor, Vertica, 1985, 9, (3), pp 273–284.Google Scholar
7. Achacte, M. and Polychroniadis, M. Development of an experimental system for active control of vibration in helicopters – development methodology for an airborne system, Vertica, 1987, 11, (1/2), pp 123–138.Google Scholar
8. Shaw, J., Albion, N., Hanker, E.J. and Teal, R.S. Higher harmonic control: wind tunnel demonstration of fully effective vibratory hub force suppression, J Amer Heli Soc, 1989, 34, (1), pp. 14–25.Google Scholar
9. Nguyen, K. and Chopra, I. Application of higher harmonic control (HHC) to hingeless rotor systems, 1989, proceedings of the AIAA/ASME/ASCE/AHS/ASC 30th Structures, Structural Dynamics, and Materials Conference, Part I, AIAA, Washington, DC, pp 507–520.Google Scholar
10. Robinson, L.H. and Friedman, P.P. Analytical simulation of higher harmonic control using a new aeroelastic model, 1989, proceedings of the AIAA/ASME/ASCE/AHS/ASC 30th Structures, Structural Dynamics, and Materials Conference, Part 3, AIAA, Washington, DC, pp 1394–1406.Google Scholar
11. Kube, R. Aeroelastic effects of helicopter vibration reduction by higher harmonic control, 1991, proceedings of the International Forum on Aeroelasticity and Structural Dynamics, German Society for Aeronautics and Astronautics (DGLR), Bonn, Germany, pp 496–504.Google Scholar
12. Bielawa, R.L. Rotary Wing Structural Dynamics and Aeroelasticity, 1992, AIAA Education Series, Prezemieniecki, J.S. (Ed).Google Scholar
13. Nitzsche, F. and Breitbach, E.J. Using adaptive structures to attenuate rotary wing aeroelastic response, J Aircr, 1994, 31, (5), pp 1178–1188.Google Scholar
14. Nitzsche, F. A comparative study on different techniques to control rotary wing vibration using smart structures, Aeronaut J, 1999, 103, (1027), pp 429–434.Google Scholar
15. Chopra, I. Development of a smart rotor, 1993, proceedings of 19th European Rotorcraft Forum, Associazione Italiana di Aeronautica Ed Astronautica, Cernobbio, Italy, pp N6.1–N6.18.Google Scholar
16. Houbolt, J.C. and Brooks, G.W. Differential equations of motion for combined flapwise bending, chordwise bending, and torsion of twisted, nonuniform rotor blades, 1958, NACA Report 1346, pp 179–195 Google Scholar
17. Young, M.I. A theory of rotor blade motion stability in powered flight, J Amer Heli Soc, 1964, 9, (3), pp 12–25.Google Scholar
18. Mil, M.L., Nekrasov, A.V., Braverman, A.S. Grodlko, L.N. and Leykand, M.A., Helicopters, calculation and design, Aerodynamics, 1967, 1, NASA TT F-494.Google Scholar
19. Arcidiacono, P.J. Prediction of rotor instability at high forward speeds, steady flight differential equations of motion for a flexible helicopter blade with chordwise mass unbalance, 1969, USAAVLABS TR 68-18A.Google Scholar
20. Ormiston, R.A. and Hodges, D.H. Linear flap-lag dynamics of hinge-less helicopter rotor blades in hover, J Amer Heli Soc, 1972, 17, (2), pp 2–14.Google Scholar
21. Friedman, P. and Tong, P. Dynamic nonlinear elastic stability of helicopter rotor blades in hover and forward flight, 1972, ASRL-TR-116-3, Massachusetts Institute of Technology, NAS2-6175, NASAR 114485.Google Scholar
22. Hodges, D.H. and Ormiston, R.A. Stability of elastic bending and torsion of uniform cantilevered rotor blades in hover, 1973, proceedings of the AIAA/ASME/ASCE/AHS/ASC 14th Structures, Structural Dynamics, and Materials Conference, Williamsburg, Virginia, AIAA Paper 73-105.Google Scholar
23. Hodges, D.H. and Dowell, E.H. Nonlinear equations of motion for the elastic bending and torsion of twisted nonuniform rotor blades, 1974, NASA TN D-7818.Google Scholar
24. Hodges, D.H. and Ormiston, R.A. Stability of elastic bending and torsion of uniform cantilever rotor blades in hover with variable structural coupling, 1976, NASA TN D-8192Google Scholar
25. Nitzsche, F., Grewal, A. and Zimcik, D. Structural component having means for actively varying its stiffness to control vibration, 1999, U.S. Patent No 5 973 440. European Patent EP-996570-B1.Google Scholar
26. Nitzsche, F. Aeroelastic analysis of a rotor blade with active impedance control at the root, Canadian Aeronautics and Space J, 2001, 47, (1).Google Scholar
27. Young, C. and Zimcik, D.G., Wickramasinghe, V.K. and Nitzsche, F. Development of the smart spring active vibration control of helicopter blades, J Intelligent Material Systems and Structures (accepted for publication 2003).Google Scholar
28. Nitzsche, F., Zimcik, D., Wickramasinghe, V. and Yong, C. Control laws for an active tunable vibration absorber designed for aeroelastic damping augmentation, Aeronaut J, January 2004, 108, (1079), pp 35–42.Google Scholar
29. Nitzsche, F., Harold, T., Wickramasinghe, V.K., Young, C. and Zimcik, D.G. Development of a maximum energy extraction control for the smart spring, 2003, proceedings 14th International Conference on Adaptive Structures and Technology, 7-9 October 2003, Seoul, Korea (to be published).Google Scholar
30. Nitzsche, F., Solaiman, S. and Afagh, F. Smart blade effects on the aeroelastic characteristics of helicopter rotors, 1999, proceedings of CEAS Forum on Aeroacoustics of Rotors and Propellers, Rome, Italy, 9-11 June 1999, pp 119–131.Google Scholar
31. Greenberg, J.M. Airfoil in sinusoidal motion in a pulsating stream, 1947, NACA TN-1326.Google Scholar
32. Morozova, N. Dynamic Stability Analysis of a Helicopter Blade with Adaptive Damper, 2002, MSc thesis, Dept of Mechanical and Aerospace Engineering, Carleton University, Ottawa, Canada.Google Scholar