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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 attachments to orbiting spacecraft are prone to thermally induced vibrations as they enter and exit the Earth’s shadow zone. Such movement of flexible attachments will generate perturbed bending moment acting on the main body of the spacecraft, which will have a significant impact on the attitude and attitude of the spacecraft. In this paper, a thermo-structural dynamic coupled finite element method is developed for the actual spacecraft rigid body-attachments coupling system. The equation of state of the coupled system includes both the nonlinear transient heat conduction equation coupled with the rigid body rotation of the spacecraft and the deformation of the flexible attachment structure and the structural dynamic equation associated with the transient temperature field. In this paper, a simple hub-beam spacecraft system is taken as the research object, and the coupled system is separately thermally-unstructured and coupled. Among them, the thermo-structure uncoupled FEA results show good agreement with the existing theoretical solutions. The thermo-structure coupled FEA results show that thermal chatter may occur under some conditions of the spacecraft.