中心舱体与薄壁梁刚-柔耦合系统的热弹性-结构动力学分析

空间柔性结构受太阳热流冲击而诱发的振动是导致航天器失效的典型模式之一，准确预测结构热致振动的响应及稳定性是卫星设计的基础。针对常见的中心舱体与附属薄壁杆件组成的空间结构，提出了考虑刚-柔耦合、耦合热弹性和耦合热-结构三重耦合效应的热致振动分析理论模型。其中，刚-柔耦合是指舱体姿态角、顶端集中质量转动与柔性附件运动的耦合；耦合热弹性是指应变率与温度场的耦合；耦合热-结构是指舱体转动及结构变形与薄壁杆件吸收太阳热流的耦合。基于热弹性理论和Lagrange方程，推导了传热和运动的耦合方程；采用Laplace变换方法并使用Routh-Hurwitz稳定判据推导了稳定性边界方程。结果表明，该模型能够更为准确的给出热致振动响应及稳定性预测。

Thermoelastic-Structural Dynamics Analysis of Rigid-Flexible Coupling System for the Hub with a Thin-Walled Beam

Thermally induced vibrations of flexible structures of spacecraft appendages are a typical one of the spacecraft failure causes. The flexible structures are usually subjected to the thermal shock from solar flux due to night-day transition in the orbit. Therefore during the satellite design, it is a basis for making an accurate prediction of responses and stability of thermally induced dynamics. A new analysis model for thermally induced vibrations of a spacecraft structure composed of a rigid cabin and a flexible thin-walled tube was proposed. In this model, the effect of rigid-flexible coupling, the coupled thermoelastic effect, and the coupled thermal-structural effect were considered simultaneously. The rigid-flexible coupling includes the attitude angle of cabin, the rotation of tip mass, and the rigid motion and elastic deformation of thin-walled tube. The coupled thermo-elasticity that assumes the strain rate coupling term exists in the heat conduction equation due to the fact that the work done by external forces should be included in the energy conservation equation. The coupled thermal-structural analysis model that takes into account of the effects of rigid rotation and elastic deformation on the absorbed solar flux by the outside surface of thin-walled tube. First, the heat conduction equation with the above three coupling effects were given by applying the principle of conservation of energy and based on thermo-elasticity theory. The governing equations of motion with thermal effect were derived by using the Lagrange equation and the assumptions of small rigid body motion and small elastic deformation. Then, these equations were solved analytically by means of the approximating temperature and displacement fields, and the equation of stability boundary was obtained by the Routh-Hurwitz criterion. The results of numerical examples indicate that the analysis model presented in this article can give more accurate predictions for dynamical responses and stability criterion of thermally induced vibrations of spacecraft structures.