AUDIBLE NOISE AND MICROGRAVITY CONTROL OF PRESSURIZED MODULEUNDER ON-ORBIT VIBRO-ACOUSTIC ENVIRONMENT

摘要

On-orbit Vibro-acoustics has found excitingapplications in modern manned space systems becauseof audible noise/human vibration requirements aimed athuman comfort and micro-gravity requirementdemanded to have suitable conditions for scientificinvestigations. Due to the severity of these requirementswhich implies a system vibro-acoustic control over awide range of frequencies, the classical design needsstrong updating in terms of physical representation ofthe mechanical system and in terms of analysisapproach. Particularly, central aspects are the on-boarddisturbance sources experimental characterisation, thesimulation of the internal acoustic cavity behaviourcoupled with the structural behaviour and the use ofboth deterministic and statistical numerical approachesas complementary tools to assess the requirementcovering the whole frequency range of interest. Theintegrated test/analysis control approach developed byAlenia Spazio covers both the evaluations of theStructural and Vibro-Acoustic transmission paths andthe characterisation of the disturbers in terms of force atthe equipment interfaces and SPL in the surroundingvolume. A dedicated methodology on how to deriveexperimentally the induced disturber's interface forcingfunctions was also developed in the frame of thismethod. In this paper, results of MPLM, NODE 2 andCOLUMBUS Modules Design & Verification activitiesversus the ISS Micro-g and Audible Noise requirementsare presented.