Research Papers

Helicopter Ground Resonance Phenomenon With Blade Stiffness Dissimilarities: Experimental and Theoretical Developments

[+] Author and Article Information
Leonardo Sanches

Faculty of Mechanical Engineering,
Federal University of Uberlândia,
Av. João Naves de Ávila, 2121—Bloco 1R,
Santa Mônica, Uberlândia, MG 38400-902, Brazil
e-mail: ls.leonardosanches@gmail.com

Guilhem Michon

Institut Clémant Ader, ISAE,
Université de Toulouse,
Toulouse 31055,France
e-mail: guilhem.michon@isae.fr

Alain Berlioz

Insitut Clémant Ader, UPS,
Université de Toulouse,
Toulouse 31077,France
e-mail: alain.berlioz@univ-tlse3.fr

Daniel Alazard

Département Mathématique,
Informatique et Automatique, ISAE,
Université de Toulouse,
Toulouse 31055,France
e-mail: daniel.alazard@isae.fr

1Corresponding author.

Contributed by the Design Engineering Division of ASME for publication in the JOURNAL OF VIBRATION AND ACOUSTICS. Manuscript received September 19, 2012; final manuscript received March 23, 2013; published online June 28, 2013. Assoc. Editor: Olivier A. Bauchau.

J. Vib. Acoust 135(5), 051028 (Jun 28, 2013) (7 pages) Paper No: VIB-12-1263; doi: 10.1115/1.4024217 History: Received September 19, 2012; Revised March 23, 2013

Recent works have studied ground resonance in helicopters under the aging or damage effects. Indeed, blade lead-lag stiffness may vary randomly with time and differ from blade to blade. The influence of stiffness dissimilarities between blades on the stability of the ground resonance phenomenon was determined through numerical investigations into the periodic equations of motion, treated using Floquet's theory. A stability chart highlights the appearance of new instability zones as a function of the perturbation introduced on the lead-lag stiffness of one blade. In order to validate the theoretical results, a new experimental setup was designed and developed. The ground resonance instabilities were investigated using different rotors and the boundaries of stability were determined. A good correlation between both theoretical and experimental results was obtained and the new instability zones, found in asymmetric rotors, were verified experimentally. The temporal responses of the measured signals highlighted the exponential divergence in the instability zones.

Copyright © 2013 by ASME
Your Session has timed out. Please sign back in to continue.



Grahic Jump Location
Fig. 1

Representation of the mechanical model

Grahic Jump Location
Fig. 2

The final design of the experimental helicopter for ground resonance analysis

Grahic Jump Location
Fig. 3

The experimental setup: (a) global view and (b) detailed view

Grahic Jump Location
Fig. 4

Blade oscillations with set 1 of blade laminas in panel (a) and its frequency spectrum diagram in panel (b)

Grahic Jump Location
Fig. 5

Comparison between the numerical and experimental instability prediction for IR configuration

Grahic Jump Location
Fig. 6

Time history of the experimental helicopter with IR configuration at Ω ≈ 7.5 Hz; (a) blades and (b) fuselage accelerations

Grahic Jump Location
Fig. 7

Rotor deformation shape for the experimental helicopter EH with IR at Ω ≈ 7.5 Hz

Grahic Jump Location
Fig. 8

Comparison between the numerical and experimental instability prediction for AR configuration

Grahic Jump Location
Fig. 9

Time history of the experimental helicopter with AR configuration at Ω ≈ 2.5 Hz; (a) blades and (b) fuselage accelerations




Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In