Inspecting the characterisation of microvibration sources

Copyright ©2014 by the International Astronautical Federation. All rights reserved.Microvibrations of a reaction wheel assembly are commonly investigated in either hard-mounted or coupled boundary conditions, although coupled wheel-structure disturbances are more representative than the hard-mounted disturbances. With the aim to reproduce the dynamics between a reaction wheel and its supporting structure, the dynamic mass (or its inverse, the accelerance) of the wheel and the driving point accelerance of the supporting structure have to be evaluated. This usually involves a series of experiments to characterise the hardware and produce exemplary models. Here a methodology is presented which has been shown to produce good estimates over a wide frequency range using a less complex test campaign. In addition, a practical example of coupling between a reaction wheel assembly and a structural panel, where the coupled loads have been estimated using the mathematical model and compared with experimental results, will be presented. Moreover, indications of the level of accuracy that can be expected from this type of analyses will be given herein