Abstract
A model based study on active control of multiple wave transmission in helicopter gearbox support struts is presented. The problems associated with transmission of structure-borne noise into helicopter cabin from its rotating components such as main rotor hub, gearbox, tail rotor etc. pose severe constraints in the service life of the structural components and on-board instrumentation. There is also a low frequency disturbance due to transient aerodynamics surrounding the rotor plane in addition to the steady state rotor harmonics. In this paper the analysis of active gearbox support strut mechanics is carried out and related complexities in modeling the closed-loop structure-control interaction is addressed. Unlike the previously available studies, finite cylindrical strut with distributed actuator dynamics and near-field effects on the sensors are considered. The computational strategy is based on a recently proposed model called Active Spectral Element Model (ASEM). This model, which is a displacement based, finite element type discretized model in the Fourier domain, can be used for developing “realistic” models of integrated active strut systems on which the gearbox is mounted. The development of a multi-input-multi-output feedback controller based on ASEM is also presented along with a discussion of the numerical implementation. Different cases illustrating control of axial wave, flexural wave, and axial-flexural coupled wave transmission through gearbox support struts are presented. The importance of considering actuator dynamics, coupling between axial, flexural and torsional waves, and actuator-sensor configurations are brought forth in this work. The efficiency of a closed-loop scheme based on velocity feedback is also demonstrated. This study shows that such accurately modeled mechanics integrated with control system parameters appears to be far better behaved when compared with the control system purely based on estimation of error signals.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Staple, A.E. and Wells, D.M. (1990) The Development and Testing of an Active Control of Structural Response System for the EH101 Helicopter, Proceedings of the 16th European Rotorcraft Forum, III. 6.1.1–III.6.1.11.
Vignati, G. (1993) Research on Helicopter Interior Noise: A Survey on Current Activities in Helicopter Industries, 2nd Community Aeronautics RTD Conf., AERO-DAYS ’93 (Naples, Italy), (Luxembourg: Commission of the European Communities, Directorate of General Science, Research and Development, pp. 493–503.
Balachandran, B. and Sampath, A. (1995) Active Interior Noise Control Studies, Proceedings of the National Technical Specialists ’ Meeting on Rotorcraft Structures, American Helicopter Society, Hampton Roads Chapter, Williamsburg, Virginia, October 31-November 2.
Pelinescu, I. and Balachandran, B. (2001) Analytical Study of Active Control of Wave Transmission Through Cylindrical Struts, Smart Materials and Structures, 10, pp. 121–136.
Staple, A.E. and MacDonald, B.A. (1993) Active Vibration Control System, US Patent, No. 5,219,143.
Sutton, T.J., Elliott, S.J., Brennan, M.J., Heron, K.H. and Jessop, D.A.C.(1997) Active Isolation of Multiple Structural Waves on a Helicopter Gearbox Support Strut, Journal of Sound and Vibration,205(1), pp. 81–101.
Nelson, P.A. and Elliott S.J. (1992) Active Control of Sound, Academic Press, London.
Elliott, S.J. and Billet, L. (1993) Adaptive Control of Flexural Waves Propagating in a Beam, Journal of Sound and Vibration, 163, pp. 295–310.
Brennan, M.J. and Pennington, R.J. and Elliot, S.J. (1994) Mechanisms of Noise Transmission Through Helicopter Gearbox Support Struts, Transactions of American Society of Mechanical Engineers, Journal of Vibration and Acoustics, 116, pp. 548–554,
Yoerkie, Jr CA., Newington, J., Welsh, W. A., Haven, N. and Sheehy, H. (1994) Helicopter Active Noise Control System, US Patent, No. 5,310,137.
Millot, T.A., Welsh, W.A., Yoerkie, Jr C.A, MacMartin, D.G. and Davis, M.W. (1998) Flight Test of an Active Gear-mesh Noise Control on the S-76 Aircraft, 54th Annual Forum of the American Helicopter Society(Washington, DC), pp. 241–249,
Ortel, D. and Balachandran, B. (1999) Control of Flexural Wave Transmission Through Struts, Proceedings of the SPIE Smart Structures and Materials Conference on Smart Structures and Integrated Systems, Newport Beach, CA, 3668(2), pp. 567–577.
Roy Mahapatra, D., Gopalakrishnan, S. and Balachandran, B. (2001) Active Feedback Control of Multiple Waves in Helicopter Gearbox Support Struts: An Active Spectral Element Model (ASEM), Smart Materials and Structures10(5), pp 1046–1058.
Doyle, J.F. (1989) Wave Propagation in Structures, Springer-Ver lag, NY.
Doyle, J.F. (1988) A Spectrally Formulated Finite Element for Longitudinal Wave Propagation, International Journal of Analytical and Experimental Modal Analysis, 3, pp. 1–5.
Doyle, J.F. and Farris, T. N. (1990) A Spectrally Formulated Finite Element for Flexural Wave Propagation in Beams, International Journal of Analytical and Experimental Modal Analysis, 5, pp. 13–23.
Gopalakrishnan, S., Martin, M. and Doyle, J.F. (1992) A Matrix Methodology for Spectral Analysis of Wave Propagation in Multiple Connected Timoshenko Beam, Journal of Sound and Vibration, 158, pp. 11–24.
Miller, D.W. and von Flotow, H. (1989) A Traveling Wave Approach to Power Flow in Structural Networks, Journal of Sound and Vibration, 128 (1), pp. 145–162.
von Flotow, A.H. (1986) Disturbance Propagation in Structural Networks, Journal of Sound and Vibration, 106, pp. 433–450.
Pan, J. and Hansen, C. H. (1991) Active Control of Total Vibratory Power Flow in a Beam. I: Physical System Analysis, Journal of Acoustical Society of America, 89(1), pp. 200–209.
Gardonio, P. and Elliott, S.J. (1996) Active Control of Wave in a One-dimensional Structure with Scattering Termination, Journal of Sound and Vibration, 192, pp. 701–730.
von Flotow, A.H. (1986) Travelling Wave Control for Large Spacecraft Structures, Journal of Guidance, 9, pp. 462–468.
Clark, R.L. and Pan, J. and Hansen, C.H. (1992) An Experimental Study of multiple Wave Types in Elastic Beams, Journal of Acoustical Society of America, 89(1), pp. 871–876.
Pelinescu, I. and Balachandran, B. (2000) Analytical and Experimental Investigations into Active Control of Wave Transmission Through Gearbox Struts, Proceedings of the SPIE Smart Structures and Materials Conference on Smart Structures and Integrated Systems, (Newport Beach, CA), 3985.
Butler, J.L. (1988) Application Manual for the Design of ETREMA Terfenol-D Magnetostrictive Transducers, (Ames, IA: EDGE Technologies Incorporated). IEEE (1991) Standard on Magnetostrictive Materials: Piezomagnetic Nomenclature, New York: The Institute of Electrical and Electronics Engineers, No. 319–1990.
Song, O. and Liberescu, L. (1997) Structural Modeling and Free Vibration Analysis of Rotating Composite Thin-Walled Beams, Journal of the American Helicopter Society, pp. 358–369.
Cowper, G. R. (1996) The Shear Coefficient in Timoshenko’s Beam Theory, Journal of Applied Mechanics, 33, pp. 335–340.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2002 Springer Science+Business Media Dordrecht
About this paper
Cite this paper
Gopalakrishnan, S., Mahapatra, D.R. (2002). Active Control of Structure-Borne Noise in Helicopter Cabin Transmitted Through Gearbox Support Strut. In: Munjal, M.L. (eds) IUTAM Symposium on Designing for Quietness. Solid Mechanics and Its Applications, vol 102. Springer, Dordrecht. https://doi.org/10.1007/978-94-017-0095-5_7
Download citation
DOI: https://doi.org/10.1007/978-94-017-0095-5_7
Publisher Name: Springer, Dordrecht
Print ISBN: 978-90-481-6081-5
Online ISBN: 978-94-017-0095-5
eBook Packages: Springer Book Archive