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Validation of lightweight antenna reflector model for environmental acoustic testing operating conditions

Book Contribution - Book Chapter Conference Contribution

© The Society for Experimental Mechanics, Inc. 2019. Environmental testing is required in the space industry to evaluate the survivability of space hardware to the launch environment. Such hardware is designed according to high demands in terms of performance and lightweight (e.g. aiming to maximise the payload weight and increase fuel efficiency). Solar panels and antenna reflectors, typically made of carbon fiber reinforced polymers and honeycomb, are examples of sub-systems presenting large surfaces of lightweight materials which are particularly sensitive to acoustic loads. Environmental acoustic testing consists in reproducing the acoustic field of a Launch Vehicle (LV) with acoustic power distribution comparable to the operating conditions. The standard way to reproduce the acoustic loading is the so-called Reverberant Field Acoustic eXcitation (RFAX) test, which is a rather costly and time consuming test method. Therefore, at sub-system level, other dynamic tests than acoustic (especially those for model validation) are performed only if strictly necessary. An alternative to RFAX is Direct Field Acoustic eXcitation (DFAX) testing. This test method has emerged as a more cost-efficient qualification technique which, in addition, presents features to potentially improve the reproducibility of the launch environment (e.g. explicit setting of the acoustic field spatial correlation properties). In this paper, Operational Modal Analysis (OMA) is applied aiming to determine the dynamic characteristics of a parabolic-shape antenna reflector for DFAX operating conditions. This approach explores the possibility to exploit data collected during qualification tests also for modal model validation purposes. The objective of this research is the validation of the lightweight antenna reflector model by correlating numerical modal analysis results against OMA results. Modal-based correlation techniques followed by sensitivity analysis, help on error localisation and on the selection of proper model updating parameters. Then, the output of this correlation study allows updating the model, bringing the numerical modal model in better agreement with the experimental data acquired during the environmental acoustic test.
Book: Conference Proceedings of the Society for Experimental Mechanics Series
Pages: 87 - 104
ISBN:9783319747927
Publication year:2019
BOF-keylabel:yes
IOF-keylabel:yes
Authors from:Private, Higher Education