Splitting the triple frequency of oscillations of an elastic structure comprising perpendicular rotors

One of the most common ways to control the angular position of a spacecraft is to use a rotor (flywheel). Rotational speed of the flywheel can reach several thousand RPM. Usually, several rotors for the pitch, roll, and yaw channels are installed on the elastic structure of a spacecraft. It is known that one rotor or a system of rotors with parallel axes of rotation combines two oscillation channels. Thus, there is a gyroscopic effect due to double frequency splitting. The paper describes vibrations of an elastic structure comprising two rotors with perpendicular axes of rotation. It is shown that the rotors combine three oscillation channels and triple frequency splitting is observed. The study consists of experimental and computational parts. A test multimass gyroscopic model with nine degrees of freedom is considered along with a computer model of a beam created within MSC.MDNastran.Rotordynamics. The results of calculation and experimental results are in good agreement and will be useful in the development of spacecraft stabilization and attitude control systems.

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