【作者】 黄志鹏；

【导师】 梁迎春；

【作者基本信息】 哈尔滨工业大学 ， 机械制造及其自动化， 2007， 硕士

【摘要】 星载机构在宇宙空间运行,工作期间要承受复杂辐射环境的影响,并周期性的进入地球日照区及阴影区。在这种条件下,星载机构超过许用范围的极限温度或温度波动会影响其内部仪器设备的正常工作。并且,非均匀的温度场及材料热物理性质的差异必然导致热应力及热变形的产生。因此,为了得到空间环境对星载二轴转台的综合热影响,本文采用有限元方法对其进行了热耦合场的分析。首先,本文在总结热结构力学有限元分析理论的基础上计算了星载二轴转台所受各种热辐射载荷,并以等效热流密度的形式将其加载到星载二轴转台的受载面上。经过求解,本文得到了星载二轴转台在轨运行期间的温度极值及温度场分布云图,跟踪了星载二轴转台五处关键位置在一周期内的温度变化,并对所得温度场及温度变化曲线进行了分析。其次,以热分析结果作为结构分析的初始条件对星载二轴转台进行了热-结构耦合分析,得到了转台结构在轨运行期间的热应力及热变形极值,跟踪了星载二轴转台五处关键位置在一周期内热应力及热变形的变化,对热应力和热变形等值云图及其变化趋势曲线进行了分析。此外,由于星载二轴转台经历循环热载荷的作用,本文对其进行了疲劳寿命校核分析。通过热-结构耦合分析,得到了星载二轴转台的结构综合热响应结果。最后,建立了一种用于热辐射分析的空间点光源辐射模型,给出了模型理论和模型参数。通过对简单圆筒结构分别应用等效热流密度加载模型和空间点光源辐射模型进行热分析,验证了空间点光源辐射模型的有效性。既而,使用空间点光源辐射模型对星载二轴转台进行了二次热分析。通过对比分析,空间点光源辐射模型对于复杂热辐射分析具有更高的准确性和更大的灵活性。更多还原

【Abstract】 Working in the space, the satellite subassembly must endure more complicated radioactive environment, it will also enter into the sunshine and the earth shadow periodically. Under this condition, the extreme temperature and the temperature fluctuation of satellite subassembly which exceed the permission may influence the working of the instruments inside. Also, the uneven temperature field and the difference of thermophysical properties will result in production of thermal stress and deformation. In order to acquire the compositive influence of space environment, the study on thermal coupling field of satellite two-axis table is done.Firstly, based on the finite element theory of thermal coupling field, all kinds of radiation loads are calculated in this paper, and the loads are applied to the satellite two-axis table in form of equivalent heat flux. The extreme temperature value and field of satellite two-axis table under working are acquired, also, this paper tracks the temperature fluctuation of five key positions on the two-axis table, the analyses of temperature field and curves are performed.Secondly, taking the temperature field as initial conditions, the thermal-structure coupling analysis is performed, the thermal stress and deformation of the two-axis table in the orbit are gained. The paper also acquires thermal stress and deformation fluctuation of the same five key positions in one cycle, both the chorograms and the fluctuation curves of stress and deformation are studied. Moreover, the two-axis table suffers effects of periodic thermal loads, so, the fatigue life is calculated and checked. By the thermal-structure coupling analysis, all the thermal coupling responses of satellite two-axis table are acquired.Finally, a new model used for radiation analysis called space pointolite radiation model is given out. By the thermal analysis of cylinder structure with the equivalent heat flux load model and the space pointolite radiation model, the availability of later is proved. Then, the thermal analysis of the two-axis is performed again with the space pointolite radiation model. After comparing, the space pointolite radiation model is believed to be more accurate and more flexible.更多还原