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Advances in Aircraft and Spacecraft Science Volume 3, Number 3, July 2016 , pages 271-298 DOI: https://doi.org/10.12989/aas.2016.3.3.271 |
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Passive suppression of helicopter ground resonance instability by means of a strongly nonlinear absorber |
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Baptiste Bergeot, Sergio Bellizzi and Bruno Cochelin
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| Abstract | ||
| In this paper, we study a problem of passive suppression of helicopter Ground Resonance (GR) using a single degree freedom Nonlinear Energy Sink (NES), GR is a dynamic instability involving the coupling of the blades motion in the rotational plane (i.e. the lag motion) and the helicopter fuselage motion. A reduced linear system reproducing GR instability is used. It is obtained using successively Coleman transformation and binormal transformation. The analysis of the steadystate responses of this model is performed when a NES is attached on the helicopter fuselage. The NES involves an essential cubic restoring force and a linear damping force. The analysis is achieved applying complexification-averaging method. The resulting slow-flow model is finally analyzed using multiple scale approach. Four steady-state responses corresponding to complete suppression, partial suppression through strongly modulated response, partial suppression through periodic response and no suppression of the GR are highlighted. An algorithm based on simple criterions is developed to predict these steady-state response regimes. Numerical simulations of the complete system confirm this analysis of the slow-flow dynamics. A parametric analysis of the influence of the NES damping coefficient and the rotor speed on the response regime is finally proposed. | ||
| Key Words | ||
| helicopter ground resonance; passive control; nonlinear energy sink; relaxation oscillations; strongly modulated response | ||
| Address | ||
| Baptiste Bergeot: INSA Centre Val de Loire, Université François Rabelais de Tours, LMR EA 2640, Campus de Blois, 3 Rue de la Chocolaterie, CS 23410, 41034 Blois Cedex, France Sergio Bellizzi and Bruno Cochelin :LMA, CNRS UPR7051, Aix-Marseille Univ., Centrale Marseille, F-13402 Marseille Cedex 20, France | ||
