Analysis of Temperature Effects on Nonlinear Dynamical Behavior of Satellite Reaction Wheels Using Multiple Scale Method

Nonlinear vibration analysis of the reaction wheel based on rotating shaft/disk model with elastic bearings which subjected to temperature changes is investigated. The rotating shaft has been modeled by the Timoshenko beam theory and elastic bearing model consists of a nonlinear spring and linear damping characteristics. Gyroscopic effects and disk imbalance forces, as well as the couplings associated with the shear deformation have been considered in the equation of motion. Temperature changes (increase or decrease) is appeared in system as an axially load when the supports of the rotor do not allow the shaft to move in axial direction. The method of multiple scales has been applied directly to solve nonlinear mathematical model and hence obtain the nonlinear dynamic response of the rotor system. Numerical simulations are based on a real reaction wheel parameters. The resonant curves have been plotted in time and frequency domain and discussed w/wo temperature changes. It has been shown that temperature changes significantly affects the dynamic behavior of the rotor system leading to resonant hard spring type curves.