Solarelastic Stability of Solar Sail Structures
Samuel Gibbs
Duke University
In order to avoid an unintended failure in proposed Solar Sail spacecraft due to solarelastic interactions it is important to develop an analytical framework for predicting the interaction between the solar pressure and the solar membrane. I will develop a fully coupled membrane, solar pressure model that can be used to predict dynamic instabilities for Solar Sails. Many of the techniques will be directly borrowed from supersonic aeroelastic analysis but the analysis will specifically focus on proposed Solar Sails. Specifically I will couple a solar pressure model proposed by MacNeal [1] with finite element structural model of the Solar Sail to determine the critical dimensions for different solar pressure strengths. Furthermore, I will conduct non-linear structural analysis for the sails to determine the post critical behavior and ensure that the stress induced by flutter will not cause catastrophic sail failure.
In addition I will validate my theoretical model with experimentation. Because the solar pressure will not be measurable on the ground where aerodynamic forces will dominate, alternate methods of simulating the solarelastic response will be developed. For my research I will use piezoelectric patches to simulate the generalized forces in the most important structural modes. The most important structural modes will be determined by the unstable eigenvalues in the solarelastic analysis and the critical mode shape from the corresponding eigenfuctions. As with the theoretical analysis, initial simulations will be done on the simply supported rectangle case.
[1] MacNeal, R. H., Structural Dynamcis of the Heliogyro, NASA CR-1745, 1971