Innovative viscoelastic material selection strategy based on dma and mini-shaker tests for spacecraft applications

Abstract

With the increase of payload sensitivity (such as high precision optics for sub-metric imager), micro-vibration disturbances generated by spinning actuators, if not controlled, may affect on-board instruments and may worsen the quality of pictures taken by an Earth observation imager. For the last two decades, viscoelastic materials have been gradually used in isolators designed for space applications. Their attractiveness comes from their ability to act as a second order low pass filter to minimise micro-vibration forces. In this study, an innovative viscoelastic material pre-selection process has been developed to assess the mechanical and thermal properties of viscoelastic isolators during early design stages. In order to characterise the viscoelastic isolators, tests have been performed at viscoelastic material level (material characterisation) and at viscoelastic isolator level (isolator characterisation). A qualitative correlation has been established between the master curves (material characterisation) and the transmissibility curves (isolator characterisation) which leads to a possible prediction of expected isolation performances of a viscoelastic material during early design stages.