Predicting the on-orbit thermally induced vibration through the integrated numerical and experimental approach

Abstract

Thermally Induced Vibration (TIV) is a typical failure of flexible spacecraft appendages when they enter or leave the eclipse. However, it is very difficult to predict the on-orbit TIV by ground experiments mainly due to the gravity effect on these flexible structures. Using numerical predictions could be an alternative solution to this problem, if the numerical method can be verified by experimental results. For this purpose, ground TIV experiments for two slender cantilever tubes and the corresponding simulations by the Finite Element Method (FEM) are presented in this paper. This was the first time to use suspension strings to simulate the weightless on-orbit environment in TIV experiments. The nice consistence between the experimental and numerical results demonstrates that the Fourier FEM can successfully simulate the TIV responses. Thus, one can expect reliable numerical predictions of the on-orbit TIV based on the Fourier FEM model calibrated by the ground experiment. Besides, the classical Boley number defined for ideal step-wised heat flux is modified to an effective Boley number, which can evaluate the TIV intensity due to the ramped heat flux in practice.