模块化空间可展开天线支撑桁架结构的热-结构分析

对模块化空间可展开天线支撑桁架结构进行空间热交变环境下的热 结构分析，为天线结构因热致变形影响形面精度和网面稳定性提供合理的防护建议。采用ANSYS APDL有限元软件建立了大口径模块化空间可展开天线支撑结构的精细化数值模型，基于已有试验分别验证了模块化可展开天线结构有限元建模和热分析模型的正确性；分析了在瞬态温度场作用下约束位置等参数对支撑桁架弦杆及拉索应力的影响和热致变形规律。研究结果表明：空间可展开天线结构的应力和变形随时间历程发展与瞬态温度场变化趋势基本一致；同一瞬态温度场下，天线结构中心模块拉索热应力最大，同圈模块的弦杆热应力幅值基本相同，其上弦杆热应力逐圈增大，而拉索热应力逐圈减小；天线结构热致变形在距离约束最远端处整体累计值最大，上层中心点处累计热致变形可达15mm左右，对天线形面精度的影响不可忽略；将天线支撑桁架结构最外侧且距离结构中心最近的模块顶角和与相邻模块竖杆拼接处作为星载天线伸展臂约束时，天线结构的热致变形最小。将该处作为模块化空间可展开天线的展开支点，并建议对天线支撑结构表面采用涂刷隔热防护复合材料涂层等防护措施，以增加天线结构在太空极端环境的适应性，从而减小温度交变对天线整体形变和网面精度的影响。

Thermal-structure analysis of modular space deployable antenna support truss structures

The thermal-structure analysis of modular space deployable antenna support truss structure under space thermal alternation is studied，and reasonable protection suggestions are provided for antenna structure's influence on antenna alignment accuracy and network stability due to thermal deformation.A fine numerical model of large aperture modular spatial deployable antenna support structure was established by ANSYS APDL finite element software.Based on the existing experiments，the correctness of finite element modeling and thermal analysis model of modular deployable antenna structure was verified respectively.The influence of constraint position and other parameters on the stress and heat-induced deformation of truss chord and cable under transient temperature field is analyzed.The results show that the development of stress and deformation time history of spatial deployable antenna is basically consistent with the change trend of transient temperature field.Under the same transient temperature field，the thermal stress of the cable in the center module of the antenna structure is the largest，the thermal stress amplitude of the chords of the same circle module is basically the same，the thermal stress of the upper chord increases，and the thermal stress of the cable decreases.The cumulative thermal deformation of the antenna structure is the largest at the farthest end of the distance constraint，and the cumulative thermal deformation at the upper center point can reach about 15mm，which can not be ignored.The thermal deformation of the antenna structure is the least when the tip angle of the module closest to the center of the structure and the joint of the vertical rod with the adjacent module are used as the constraints of the antenna extension arm.In order to reduce the influence of the transient temperature field on the shape precision and deformation of the antenna structure，it is suggested to adopt thermal control coating to improve the adaptability of the antenna structure.