中心舱体-附件耦合系统热颤振有限元分析  

Thermal flutter analysis of a spacecraft with a flexible appendage based on FEM

作　　者：薛明德[1] 李伟[1] 向志海[1] 

机构地区：[1]清华大学工程力学系,北京100084

出　　处：《清华大学学报（自然科学版）》2008年第2期270-275,共6页Journal of Tsinghua University(Science and Technology)

基　　金：国家"八六三"高技术项目(863-2-2-1-9)

摘　　要：在轨航天器的柔性附件在其进出地球阴影区时很容易发生热诱发振动现象。柔性附件的这种运动将会产生扰动弯矩作用于航天器主体之上,从而对航天器的姿态运动产生重要影响。该文针对实际航天器刚体-附件耦合系统发展了一种热-结构动力学耦合的有限元分析方法。该耦合系统的状态方程既包括与航天器刚体转动和柔性附件结构变形相耦合的非线性瞬态热传导方程,也包括与瞬态温度场相联系的结构动力学方程。该文以一个简单的hub-beam航天器系统为研究对象,对该耦合系统分别进行了热-结构非耦合和耦合分析。其中热-结构非耦合有限元分析的结果与已经存在的理论解结果显示了很好的一致性;热-结构耦合有限元分析结果表明航天器在某种条件下可能发生热颤振。Flexible appendages on spacecraft are apt to experience thermally-induced vibrations during orbital eclipse transitions. The motion of the flexible appendages can result in disturbance torques acting on the main body of the spacecraft which may significantly affect the spacecraft attitude dynamics. A finite element method was developed to study the coupled thermal and dynamics behavior of a spacecraft with a flexible appendage. The governing equations of the system include the nonlinear transient heat conduction equation, which not only considers the heat transfer by radiation but also the rigid body＇s rotations and structural deformations, and the structural dynamic equations related to the transient temperature field. Thermal-structural uncoupled and coupled analyses were carried on a simple hub-beam coupled system. The results of the uncoupled analysis are in good agreement with the theoretical results. The coupled analysis shows that unsteady vibrations and the oscillatory attitude of the spacecraft may occur.

关 键 词：航天器 热颤振 热-结构耦合 有限元 

分 类 号：V414.1[航空宇航科学与技术—航空宇航推进理论与工程]