Parametric approaches to vibration source characterization for prediction of receiver responses: case study on a reaction wheel assembly

Abstract

Parametric characterizations of a vibration source can be done in different ways depending on type of the source and their purpose. A prototype reaction wheel assembly (RWA) prepared in the laboratory is taken as the source and two parametric source characterizations are comparatively discussed in the aspect of prediction of vibration responses when the source is installed onto a simple cantilever. Both characterizations are done by modeling of dynamics inside the source, based on measurements of blocked forces and torques as functions of frequency and operation speeds. One approach is to observe overall pattern of the measurements and obtain parametric model such that it may represent the measurements best along dominant harmonics over two dimensional domain of frequency and operation speed of interest. The other approach is to observe the operation-speed-dependent spectral pattern and to parametric model such that it may represent the measurements best in frequency domain at each operation speed. Although the purpose of the first approach may not be to predict vibration responses of receiver structures, in this study, it will be used to predict to vibration responses of a simple receiver when the RWA is operated at one speed. Predictions by the second approach will be comparatively discussed.