【作者】 张弛；

【导师】 董广明；

【作者基本信息】 上海交通大学 ， 机械工程， 2021， 硕士

【摘要】 航天器在轨运行时会周期性地经历光照区和阴影区,引起结构内部产生剧烈的温度变化,进而引发热-结构振动,严重影响卫星服役性能。为保证航天器稳定、高效地工作,研究者们早已针对航天结构的热-结构特性做出了一系列研究,但目前该领域尚存在一些待解决的问题,基于商业有限元分析软件的热-结构分析流程并不完善、针对繁琐的仿真分析和热振动预测方面近些年少有人做出改进以及关于复杂激励形式下航天器结构的热振动响应规律及其有效抑制方法的研究较少。本文首先基于耦合场单元和热辐射表面效应单元建立直接耦合仿真流程,相较于间接耦合分析,直接耦合分析能够通过一次求解得出所需所有物理场的结果,求解过程也更加精确。基于此,本文给出了完整的直接耦合仿真流程。其次,针对三种典型航天器结构如薄壁圆管、太阳能帆板和环形天线在空间环境下的热-结构振动响应规律做出了研究。针对薄壁圆管进行有限元建模和求解,分析其上下表面的温度场变化趋势、热振动响应的特点和一阶固有频率对其热振动的影响规律;针对太阳能帆板往往采用的蜂窝结构建立热学和力学等效模型,简化有限元建模流程,探讨了帆板在轨热振动的规律及一阶固有频率对振动形式的影响;针对环形天线进行参数化建模,讨论了相关结构和材料参数对其热结构响应的影响规律。在航天器结构设计阶段常常需要对不同设计参数反复分析其变化对卫星在轨热振动性能的影响,为提高研发效率,基于tcl/tk软件包开发基于系统图形组件的桌面自动化仿真软件,将针对航天器典型结构的有限元建模、求解和后处理数据进行集成。在热振动预测方面,将Boley的热振动判据与直接耦合仿真相结合,提出了“基于参数的基准判据”,极大提高了分析效率。最后,针对复杂激励形式下的航天器热振动特性及抑制方法做出了研究。在周期太阳热流作用下,分析了帆板和环形天线在进、出光照区时的热振动响应;研究了在卫星自身部件不同频率的正弦激励下,机械激励与热流激励的耦合情况;最后研究了不同遮挡工况下太阳能帆板的振动形式及有效振动抑制措施。更多还原

【Abstract】 Thermal-structural vibration is induced when spacecraft experiences penumbra transition and suffers fierce temperature violence,which will affect its performance dramatically.There are still some problems undone though much research has been conducted.The procedure of thermalstructural analysis of FEA software is not clear enough.Little research has been done with regard to thermal vibration prediction.What’s more,the performance of spacecraft with complex input and its effective control methods have not been studied.First,this paper establishes directly coupled FEA procedure based on couple-field and surface effect element.In contrast with indirect analysis,it achieves more accurate results of all fields in just one solution.Then,research of thermal-structural vibration of thin-walled tubes,solar panel and circular antenna was conducted.We model and solve thinwalled tubes and analyze its trend of temperature and its difference and how its first order frequency influence its vibration.To simplify modeling process,we build thermally and structurally equivalent model of honeycomb panel and discuss how its first order frequency influence its vibration.At last,parametric model of circular antenna is established and its structural and material parameters are discussed.In design phase,the influence of different parameters on spacecraft’s vibration performance should be verified many times.To make this procedure more efficient,we developed GUI automatic FEA software based on tcl/tk package which ensemble modeling,solution and postprocessing.As for prediction of thermal vibration,we combine Boley’s theorem and ‘criteria based on parameters’ to greatly improve efficiency.Finally,we conduct research on vibration pattern under complex input and its control methods.The thermal vibration of panel and antenna under periodic heat flux are studied.The coupling effect of mechanical(sinus force with various frequency)and thermal input are analyzed.At last,vibration pattern of solar panel under some shaded occasions and its controlling strategy are discussed.更多还原