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Chapter 10 - Structural Dynamics and Liquid Sloshing

Published online by Cambridge University Press:  18 December 2014

Marcel J. Sidi
Marcel J. Sidi
Affiliation:
Israel Aircraft Industries Ltd
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Summary

Introduction

A typical spacecraft structure consists of two principal parts. The first one is the body of the spacecraft, which contains all the payload instrumentation and control hardware pertaining to the Attitude and Orbit Control System (AOCS). Its structure must be very rigid in order to withstand mechanical loads during the launch stage, and also to assure correct positioning of the control torquers and attitude sensors for achieving the necessary pointing accuracy in the s/c mission stage. The necessity to save on weight leads to mechanical design tradeoffs between weight and rigidity, which results in a body that is only quasirigid and in which structural vibration modes should be anticipated.

The second part of the spacecraft structure consists of large flexible appendages: parabolic antennae, large synthetic-aperture radar, and very large flexible solar arrays built from light materials in order to reduce their weight. Spacecraft structures are now. becoming extremely complicated because of these appendages, which also induce structural oscillation under the excitation of external torques and forces. Finally, we must likewise consider vibrations due to the liquid contained in fuel tanks. The vibrational dynamics evolving from flexible appendages and liquid sloshing interferes strongly with the attitude control dynamics, and puts severe limitations on the achievable qualities of the attitude control system (ACS).

This chapter is primarily concerned with this second class of structural vibrations. First, we must write simplified structural dynamics models for solar panels and liquid sloshing before coupling them to the rigid-body attitude dynamics of spacecraft. An analytical model for the rigid body and the flexible structural modes will allow us to evaluate the limitations on the bandwidth of the ACS.

Modeling Solar Panels

Although the techniques of structural modeling described in this chapter are applicable to any nonrigid appendage to the solid body, we will concentrate on the structural dynamics of solar panels, which are common to almost all types of satellites.

Type
Chapter
Information
Spacecraft Dynamics and Control
A Practical Engineering Approach
 , pp. 291 - 317
Publisher: Cambridge University Press
Print publication year: 1997

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References

Abramson, H. (1961), “The Dynamic Behavior of Liquids in Moving Containers,” NASA SP-106 (N67-15884), Scientific and Technical Information Division, National Aeronautics and Space Administration, Washington, DC.
Bode, H. W. (1945), Network Analysis and Feedback Amplifier Design. New York: Van Nostrand.Google Scholar
Bryson, A. (1983), “Stabilization and Control of Spacecraft,” Microfiche supplement to the Proceedings of the Annual AAS Rocky Mountain Guidance and Control Conference (5-9 February, Keystone, CO). San Diego, CA: American Astronautical Society.Google Scholar
Peterson, D., Crawley, E., and Hansman, R. (1988), “Nonlinear Fluid Slosh Coupled to the Dynamics of a Spacecraft,”AIAA Journal 27(9): 1230–40.Google Scholar
Pocha, J. (1986), “An Experimental Investigation of Spacecraft Sloshing,” Paper no. 255, Proceedings of the Second International Symposium on Spacecraft Flight Dynamics (20-23 October, Darmstadt, Germany). Paris: European Space Agency.Google Scholar
Prins, J. (1983), “Trends in AOCS Testing,” IFAC Workshop (August, Stanford, CA).
Sidi, M. (1976), “Feedback Synthesis with Plant Ignorance, Non-minimum-Phase, and Time-Domain Tolerances,”Automatica 12: 265–71.CrossRefGoogle Scholar
Sidi, M. (1980), “On Maximization of Gain-Bandwidth in Sampled Systems,”International Journal of Control 32(6): 1099–1109.CrossRefGoogle Scholar
Sidi, M., and Horowitz, I. (1973), “Synthesis of Feedback Systems with Large Plant Ignorance for Prescribed Time Domain Tolerances,”Sensitivity, Adaptivity and Optimality (Proceedings of the Third IFAC Symposium, 18-23 June, Ischia, Italy). Oxford, UK: Pergamon, pp. 202–5.Google Scholar
Thomson, W. (1988), Theory of Vibration with Applications. Englewood Cliffs, NJ: Prentice-Hall.Google Scholar
Unruh, J., Kana, F., Dodge, F., and Fey, T. (1986), “Digital Data Analysis Techniques for Extraction of Slosh Model Parameters,”Journal of Spacecraft and Rockets 23(2): 171–7.CrossRefGoogle Scholar
Weaver, W., Timoshenko, S., and Young, D. (1990), Vibration Problems in Engineering. New York: Wiley.Google Scholar
Williams, C. G. (1976), “Dynamics Modelling and Formulation Techniques for Non-Rigid Spacecraft,” Electronic and Space Systems, British Aircraft Corporation, Bristol, UK.
Williams, C., and Wood, T. (1989), “Dynamics and Formulation Techniques for Non-Rigid Spacecraft,” ESTEC contract no. 8085/88/NL/MAC,TP9257, British Aircraft Corporation, Bristol, UK.

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