DOI QR코드

DOI QR Code

Beating phenomena in spacecraft sine testing and an attempt to include the sine sweep rate effect in the test-prediction

  • Received : 2015.09.01
  • Accepted : 2015.10.31
  • Published : 2016.04.25

Abstract

The Spacecraft (S/C) numerical sine test-predictions are usually performed through Finite Element Method (FEM) Frequency Response Analysis (FRA), that is the hypothesis of steady-state responses to harmonic excitation to the S/C base is made. In the test practice, the responses are transient and may be significantly different from those predicted through FRA. One of the most significant causes of discrepancy between prediction and test consists in the beating phenomena. After a brief overview of the topic, the typical causes of beating are described in the first part of the paper. Subsequently, focus is made on the sine sweep rate effect, which often leads to have beatings after the resonance of weakly damped modes. In this work, the approach illustrated in the literature for calculating the sine sweep rate effect in the case of Single-Degree-Of-Freedom (SDOF) oscillators is extended to Multi-Degrees-Of-Freedom (MDOF) systems, with the aim of increasing the accuracy of the numerical sine test-predictions. Assumptions and limitations of the proposed methodology are detailed along the paper. Several assessments with test results are discussed and commented.

Keywords

References

  1. Calvi, A. and Nali, P. (2007), "Some remarks on the reduction of overtesting during base-drive sine vibration tests of spacecraft", ECCOMAS Conf. on Computational Methods in Structural Dynamics and Earthquake Engineering, Rethymno, Crete, Greece, June.
  2. Craig, R.R. (1981), Structural Dynamics, an Introduction to Computer Methods, John Wiley & Sons.
  3. ECSS-E-HB-32-26A (2013), Spacecraft Mechanical Loads Analysis Handbook, ECSS Secretariat ESAESTEC Requirement & Standard Division, Noordwijk, The Netherlands.
  4. Girard, A. and Roy, N. (2008), Structural Dynamics in Industry, ISTE Ltd and John Wiley & Sons.
  5. Lalanne, C. (2009), Mechanical Vibration & Shock Analysis, Vol 1: Sinusoidal Vibrations, 2nd Edition, John Wiley & Sons.
  6. Lollock, J.A. (2002), "The effect of a swept sinusoidal excitation on the response of a single-degree-offreedom oscillator", 43rd AIAA Structures, Structural Dynamics, and Materials Conference, Denver, Colorado, March.
  7. Naisse, C. and Bettacchioli, A. (2012), "Simulation des essais en vibrations de satellites a partir de l'analyse modale d'une reponse bas niveau", A.S.T.E. $n^{\circ}C$ 111.
  8. Nali, P. and Calvi, A. (2006), "An investigation on the spacecraft design loads cycles and sine vibration test", TEC-MCS/2006/1362/ln/AC, ESA, Noordwijk, The Netherlands, March.
  9. Nali, P., Mucciante, L.D. and Caccamo, L. (2013), "An easy-to-implement computational method for the spacecraft sine test-prediction with particular emphasis on the modal contributions", COMPDYN 2013, Kos Island, Greece, June.
  10. Roy, N. and Girard, A. (2012), "Revisiting the effect of sine sweep rate on modal identification", European Conference on Spacecraft Structures, Materials and Environmental Testing, Noordwijk, The Netherlands, 20-23 March.
  11. Sedaghati, R., Soucy, Y. and Etienne, N. (2003), "Efficient estimation of effective mass for complex structures under base excitations", Can. Aeronaut. Space J., 49(3), 135-143. https://doi.org/10.5589/q03-009
  12. Wijker, J. (2004), Mechanical Vibrations in Spacecraft Design, Springer.

Cited by

  1. A lower bound analytical estimation of the fundamental lateral frequency down-shift of items subjected to sine testing vol.7, pp.1, 2020, https://doi.org/10.12989/aas.2020.7.1.079