Abstract
In design and certification of spacecraft, payload/launcher coupled load analyses are performed to simulate the satellite dynamic environment. To obtain accurate predictions, the system damping properties must be properly taken into account in the finite element model used for coupled load analysis. This is typically done using a structural damping characterization in the frequency domain, which is not applicable in the time domain. Therefore, the structural damping matrix of the system must be converted into an equivalent viscous damping matrix when a transient coupled load analysis is performed. This paper focuses on the validation of equivalent viscous damping methods for dynamically condensed finite element models via correlation with experimental data for a realistic structure representative of a slender launch vehicle with solid rocket motors. A second scope of the paper is to investigate how to conveniently choose a single combination of Young’s modulus and structural damping coefficient—complex Young’s modulus—to approximate the viscoelastic behavior of a solid propellant material in the frequency band of interest for coupled load analysis. A scaled-down test article inspired to the Z9-ignition Vega launcher configuration is designed, manufactured, and experimentally tested to obtain data for validation of the equivalent viscous damping methods. The Z9-like component of the test article is filled with a viscoelastic material representative of the Z9 solid propellant that is also preliminarily tested to investigate the dependency of the complex Young’s modulus on the excitation frequency and provide data for the test article finite element model. Experimental results from seismic and shock tests performed on the test configuration are correlated with numerical results from frequency and time domain analyses carried out on its dynamically condensed finite element model to assess the applicability of different equivalent viscous damping methods to describe damping properties of slender launch vehicles in payload/launcher coupled load analysis.
Similar content being viewed by others
References
Fransen, S., Fischer, H., Kiryenko, D., Levesque, D., Henriksen, T.: Damping methodology for condensed solid rocket motor structural models. In: International Modal Analysis Conference. IMAC, Jacksonville (2010)
Araujo, X.V., Fransen, S., Grmes, S., Thiry, N.: Validation of equivalent viscous damping methodologies. CEAS Space J. 4(1), 31–39 (2013)
Bartoccini, D., Di Trapani, C., and Fransen, S.: Equivalent viscous damping methodologies applied on VEGA launch vehicle numerical model. In: European Conference on Spacecraft Structures, Materials, and Environmental Testing (2014)
ESTEC: Experimental Validation of SRM Damping Models. Statement of Work—ESA Express Procurement EXPRO (2015)
Craig, R.R., Bampton, M.C.C.: Coupling of substructures for dynamic analysis. AIAA J. 6(7), 1312–1319 (1968)
Géradin, M., Rixen, D.: Mechanical Vibrations: Theory and Applications to Structural Dynamics. Wiley, New York (1997)
Ferry, J.D.: Viscoelastic Properties of Polymers. Wiley, New York (1980)
Schaller, R., Fantozzi, G., Gremaud, G. (eds.): Mechanical Spectroscopy Q\(^-1\) 2001: with Applications to Materials Science. Trans Tech Publications, Totton (2001)
Menard, K.P.: Dynamic Mechanical Analysis. CRC Press, Taylor & Francis Group, New York (2008)
Mastroddi, F., Coppotelli, G., Trequattrini, F., Riso, C.: Experimental Validation of Solid Rocket Motor Damping Models. Final Report—ESA Express Procurement EXPRO (2017)
Anon., MSC/Nastran Dynamic Analysis User’s Guide, MSC. Software Corporation (2012)
Anon., MSC/Nastran Design Sensitivity and Optimization User’s Guide, MSC. Software Corporation (2012)
Anon., MSC/Nastran Advanced Dynamic Analysis User’s Guide, MSC. Software Corporation (2012)
Acknowledgements
The results presented in the present paper have been obtained in the research activity “Experimental Validation of SRM Damping Models” funded by ESA Estec to the Department of Mechanical and Aerospace Engineering of Sapienza University of Rome under the ESA Contract no. 4000115499/15. The authors would like to thank Corinna Cerini for her valuable contribution to the experimental activity.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Riso, C., Fransen, S., Mastroddi, F. et al. Experimental validation of solid rocket motor damping models. CEAS Space J 10, 213–230 (2018). https://doi.org/10.1007/s12567-017-0191-3
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12567-017-0191-3