Modeling of spacecraft with flexible solar panel considering thermally induced motion
Thermally induced motion of flexible solar panel have significant impact on attitude dynamics and control when the spacecraft experience eclipse transitions. Based on angular momentum theorem thermally induced attitude dynamics of rigid hub with a flexible solar panel is developed. The principle of thermally induced vibration is explained. Thermally induced disturbance toque which initiates attitude error of control system is obtained. Flexible modal response is analyzed with different position of solar panel when satellite enter or exit eclipse. Numerical simulations illustrate that thermally induced disturbance toque mainly distort yaw and roll axis attitude of spacecraft.
Coupled Thermal-Dynamic Stability Analysis of Large-Scale Space Structures by FEM
Thermally induced vibrations of flexible spacecraft appendages, which are subjected to incident solar heat flux during the orbital eclipse transitions, have been typical failure of modern spacecrafts since 1960’s. For example, this failure was observed on the Voyager space explorer [1], the Hubble Space Telescope [1] and the UARS satellite [2] etc. When the thermally-induced vibration is unstable, it is called thermal flutter, which is due to the coupling effect between structural deformations and the incident normal solar heat flux. Owing to the existence of the coupling effect and the transient heat conduction problem involving heat transfer by radiation, it is really a highly nonlinear problem.
Investigations of dielectric gratings using electrodynamic models based on volume integral equations
Eigenmodes of planar and cylindrical dielectric gratings (DGs) and electromagnetic wave scattering from multiplayer DGs are investigated. The DG characteristics are calculated using numerical-analytical solution of integral equations (IEs).