带柔性附件的中心刚体的频率特性及实验研究

从力学基本原理出发，利用有限元方法建立了由中心刚体和柔性梁组成的这类卫星－帆板模型的动力学方程，研究了该系统的刚－柔耦合频率特性，详细讨论了刚柔刚度比K′和刚柔惯量比J′对系统的频率的影响，同时利用气溪台动力学全物理仿真测试实验平台，对该刚柔耦合系统进行了动力学测试，验证了理论模型及分析的正确性，理论研究和实验结果均表明，不同的K′和J′对系统的频率有较大的影响，并且系统的主导频率会发生转移，这些为卫星等航天器的设计提供了一定的依据。

FREQUENCY CHARACTERISTICS AND EXPERIMENT INVESTIGATION ON A HUB-BEAM SYSTEM

The frequency characteristics of a hub-beam system are investigated in this paper. This rigid-flexible coupling system consists of a rigid hub, a flexible beam and a torsional spring. A finite-element model for this system is derived and all the couplings between the system rigid and flexible degrees of freedom are included. The frequency characteristics of this system are related to two ratios: the ratio J' of the beam and rigid hub inertia, the ratio K' of the torsional spring and beam bending stiffness. The effects of two ratios on the system frequencies are analyzed by numerical simulation and experimental test, respectively. The experiment is conducted in a single-axis air-bearing testbed. Both the theoretical results and experimental results show that the two ratios, i.e. K' and J', have significant influences on the system frequency characteristics. The dominant frequency of this system in steady responses can transit between the rigid and flexible frequencies in case of different values of K' and J'.