Thermally induced bending vibrations of a flexible rolled-up solar array

Abstract

An analytical approach for determining the thermal-structural response of a flexible rolled-up solar array due to a sudden increase in external heating is developed. Two analyses are presented: 1) an uncoupled thermal-structural analysis that assumes the heating and temperature gradients are not affected by thermally induced motions, and 2) a coupled thermal-structural analysis that includes the effects of structural deformations on heating and temperature gradients. The analytical methods identify key parameters for understanding the static and dynamic response. A stability criterion given in nondimensional parameters establishes the conditions for thermal flutter. Key parameters for thermal flutter include the ratio of thermal and structural response times, the solar inclination angle, and the system damping. Numerical calculations are presented for the solar arrays on the Hubble Space Telescope. Unstable oscillations are possible but are unlikely to have practical importance.