THERMALLY-INDUCED BENDING VIBRATIONS OF A FLEXIBLE ROLLED-UP SOLAR-ARRAY

An analytical approach for determining the thermal-structural response of a flexible rolled-up solar army due to a sudden increase in extern al heating is developed. Two analyses are presented: 1) an uncoupled t hermal-structural analysis that assumes the heating and temperature gr adients are not affected by thermally induced motions, and 2) a couple d thermal-structural analysis that includes the effects of structural deformations on heating and temperature gradients. The analytical meth ods identify key parameters for understanding the static and dynamic r esponse. A stability criterion given in nondimensional parameters esta blishes the conditions for thermal flutter. Key parameters for thermal flutter include the ratio of thermal and structural response times, t he solar inclination angle, and the system damping. Numerical calculat ions are presented for the solar arrays on the Hubble Space Telescope. Unstable oscillations are possible but are unlikely to have practical importance.