A Preliminary Methodology to Account for Structural Dynamics Variability of Satellites in Microvibration Analysis

Abstract

Due to constantly increasing requirements for more precise and high-resolution instrumentations, microvibration prediction represents an issue of growing importance. Hence the need of reliable analysis tools which can evaluate microvibrations effects efficiently. This paper describes how to tackle the issue of structural uncertainties in microvibration predictions. In particular, uncertainties related to the microvibration sources are analysed as well as those linked to the modelling of the structure. A methodology to define the worst case of vibration produced by on board sources is presented and compared to experimental data. Additionally, an approach to quantify the uncertainties in the Finite Element model is also described.

A semiempirical methodology to characterise a family of microvibration sources

“…This article shows that this approximation only holds in some specific circumstances, extending what has already been achieved in [15,35]. A methodology is proposed to provide better estimations of RW disturbances on the structure, allowing the evaluation of a microvibration budget at an early stage of the mission design for a family of RWs.…”

“…When it comes to the evaluation of the structural behaviour of the spacecraft, uncertainties can arise, [10]. These can be structure related, [11][12][13][14] or source related, [15]. The latter are the focus of this paper.…”

The effect of assembly and static unbalance on reaction wheel assembly bearing harmonics

“…Whilst it is known that bearing disturbances and loads are mostly created through microscopic defects [24], aside from the defect size there are many other potential parameters that can have an influence, such as bearing geometry, material or even the system configuration [25][26][27]. Imperfections in bearings can be categorised into two types, localised or continuous [28].…”