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Advances in Aircraft and Spacecraft Science Volume 5, Number 2, March 2018 , pages 187-204 DOI: https://doi.org/10.12989/aas.2018.5.2.187 |
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Sine sweep effect on specimen modal parameters characterization |
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Nicolas Roy, Maxime Violin and Etienne Cavro
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| Abstract | ||
| The sine sweep base excitation test campaign is a major milestone in the process of mechanical qualification of space structures. The objectives of these vibration tests are to qualify the specimen with respect to the dynamic environment induced by the launcher and to demonstrate that the spacecraft FE model is sufficiently well correlated with the test specimen. Dynamic qualification constraints lead to performing base excitation sine tests using a sine sweep over a prescribed frequency range such that at each frequency the response levels at all accelerometers, load cells and strain gages is the same as the steady state response. However, in practice steady state conditions are not always satisfied. If the sweep rate is too high the response levels will be affected by the presence of transients which in turn will have a direct effect on the estimation of modal parameters. A study funded by ESA and AIRBUS D&S was recently carried out in order to investigate the influence of sine sweep rates in actual test conditions. This paper presents the results of this study along with recommendations concerning the choice of methods. | ||
| Key Words | ||
| sine sweep; FRF estimation; modal identification | ||
| Address | ||
| Nicolas Roy: Top Modal, 130 rue Galilee, 31670 Labege, France Maxime Violin: Airbus Defence & Space, 31 rue des Cosmonautes, 31500 Toulouse, France Etienne Cavro: Intespace, 2 rond-point Pierre Guillaumat, 31029 Toulouse, France | ||
