Estudo de Amortecedores De Vibração para Um Helicóptero Em Ressonância de Solo

Abstract

Helicopters are characterized as rotary-wing aircraft whose lift comes from blade’s rotation. Among the movements that the blade describes during its rotational motion, the Lead-Lag is characterized as the most important of these movements for this work. This type of blade movement, under certain circumstances, can cause a dynamic imbalance in the main rotor, causing the rotor to excite the fuselage. If this excitation matches the fuselage’s natural frequency, the aircraft may enter a ground resonance condition and consequently compromise the aircraft’s structural integrity. This type of effect, in a particular case, occurs when the aircraft is on the ground supported by its landing gear, hence the name ground resonance. Some constructive characteristics of the aircraft, such as the type of main rotor, may expose the aircraft to a higher probability of occurrence of this phenomenon. Fortunately, there are some types of vibration dampers that can be implemented to modify the natural frequency of the fuselage and thus avoid the occurrence of the ground resonance effect. This work intends to compare some proposed damping models such as the Linear Damper, NES (Non-Linear Energy Sink), and TVNES (Time Variable Non-Linear Energy Sink), regarding the behavior of vibration amplitudes after the implementation of these models.