This work describes the design of a holding system for a quartz crystal micro-balance for space application. The innovative characteristics of the conceived design are related to the harsh mechanical environment and wide temperature range in which the microbalance is expected to work. In fact, the proposed solution allows withstand high loading expected at the instrument launch and offers required compliance between ambient and liquid nitrogen temperatures. Moreover, the proposed solution can be used even in ground applications (vacuum testing and laboratories), where the mechanical requirements are more relaxed but critical thermal conditions are still present. In that view, the proposed solution allows an easy replacement of the crystal in case of need and is cost effective. The design of the holding system has been driven by finite element analyses (static, thermo-elastic and modal analyses) aimed to verify the fulfillment of the thermal and mechanical requirements. Finally, a mockup of the microbalance holder has been manufactured and tested in representative mechanical environment.
Questo lavoro descrive la progettazione di un sistema di fissaggio per una microbilancia al quarzo per applicazione spaziale. Le caratteristiche innovative di questo design sono legate alle dure condizioni meccaniche ambientali e all’esteso campo di temperature in cui la microbilancia si troverà ad operare. Infatti, la soluzione proposta permette di sopportare l’elevato carico atteso al momento del lancio e offre la conformità richiesta per le temperature comprese tra quella ambientale e quella dell’azoto liquido. Inoltre, la soluzione proposta può essere usata in applicazioni terrestri (prove nel vuoto e laboratori), dove le richieste meccaniche sono molto meno demandanti ma le condizioni termiche critiche sono ancora presenti. In quest’ottica, la soluzione proposta permette una facile sostituzione del cristallo in caso di necessità ed è economica. La progettazione del sistema di fissaggio è stata guidata dall’analisi ad elementi finiti (analisi statica, termo-elastica e modale) allo scopo di verificare il raggiungimento dei requisiti meccanici e termici. Infine, un mockup del supporto della microbilancia è stato prodotto e testato in un ambiente meccanico rappresentativo.
Design and testing of the holding system for a spaceborne QCM
SOMASCHINI, RICCARDO
2016/2017
Abstract
This work describes the design of a holding system for a quartz crystal micro-balance for space application. The innovative characteristics of the conceived design are related to the harsh mechanical environment and wide temperature range in which the microbalance is expected to work. In fact, the proposed solution allows withstand high loading expected at the instrument launch and offers required compliance between ambient and liquid nitrogen temperatures. Moreover, the proposed solution can be used even in ground applications (vacuum testing and laboratories), where the mechanical requirements are more relaxed but critical thermal conditions are still present. In that view, the proposed solution allows an easy replacement of the crystal in case of need and is cost effective. The design of the holding system has been driven by finite element analyses (static, thermo-elastic and modal analyses) aimed to verify the fulfillment of the thermal and mechanical requirements. Finally, a mockup of the microbalance holder has been manufactured and tested in representative mechanical environment.File | Dimensione | Formato | |
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2017_12_Somaschini.pdf
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https://hdl.handle.net/10589/138502