摘要
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.
Thermally induced vibrations of flexible structures of spacecraft appendages are a typical cause of spacecraft failure.The flexible structures are usually subjected to the thermal shock from solar flux due to night-day transition in the orbit.Therefore,an accurate prediction of the thermally induced dynamic responses and stability is essential for satellite design.A new model for analyzing the 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 the thin-walled tube.The coupled thermo-elasticity assumes that 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 model takes into account the effects of rigid rotation and elastic deformation on the absorbed solar flux through the outside surface of thin-walled tube.First,the heat conduction equation with the aforementioned three coupling effects was given in accordance with the principle of conservation of energy and the theory of thermo-elasticity.Based on the assumptions of small rigid-body motion and small elastic deformation,the governing equations of motion with thermal effect were derived using the Lagrange equation.Then,these equations were solved analytically with approximations of the 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 presented analysis model can accurately predict the dynamic responses and stability of thermally induced vibrations of spacecraft structures.
作者
邢晓峰
沈振兴
胡国龙
张彪
Xiaofeng Xing;Zhenxing Shen;Guolong Hu;Biao Zhang(Key Laboratory of Mechanical Reliability for Heavy Equipment and Large Structures of Hebei Province,Yanshan University,Qinhuangdao,066004)
出处
《固体力学学报》
CSCD
北大核心
2021年第4期434-442,共9页
Chinese Journal of Solid Mechanics
基金
国家自然科学基金项目(11702241)资助。
关键词
航天器结构
热致振动
刚-柔耦合
耦合热弹性
耦合热-结构
spacecraft structures
thermally induced vibrations
rigid-flexible coupling
coupled thermoelastic model
coupled thermal-structural model
