Un metodo per la progettazione di smorzatori ad anello per ingranagggi di applicazione aeronautica.

In order to limit HCF damage due to high vibration amplitudes of thin-walled gears for aeronautical applications, the damping of the system is increased by means of friction ring dampers, placed into a groove and kept in contact with its base by means of the centrifugal force. In this paper, a method for the calculation of the forced response of gears for aeronautical application coupled to ring dampers is proposed. Both the gear and the ring damper are modelled by means of FEM. The two components are coupled by contact elements characterized by tangential and normal contact stiffness, Coulomb friction law and one dimensional relative motion. Due to the non-linear contact forces, the problem must be solved iteratively by using a limited set of non-linear equations. The harmonic excitation is calculated by means of Fourier analysis of the periodic force profile acting on the loaded teeth. The methodology is applied to a case of industrial interest. The effect of the principal design parameters of the ring damper which affect the dynamics of the gear is also highlighted.