星载蜂窝夹层结构固面天线反射器的热变形
Thermal distortion for honeycomb sandwich construction rigid reflector of satellite antenna

针对固面天线反射器在轨运行时自身结构因素受环境温度变化引起热变形的问题，以一口径为1.2 m的星载蜂窝夹层结构固面反射器为研究对象，首先采用有限元仿真软件详细分析了温度由20℃降到-80℃时，不同蒙皮材料、胶层厚度、蜂窝刚度和蜂窝的热膨胀系数（CTE）对反射器热变形型面精度均方根（RMS）的影响规律，其次采用热压罐成型工艺制备了M55J和T300蒙皮材料的两种典型蜂窝夹层结构反射器对仿真结果进行试验验证。结果表明：M55J蒙皮材料发射器的热变形比T300蒙皮材料反射器的小，同时发现发射器的热变形与胶层的厚度基本呈线性关系，胶层厚度越薄，反射器的热变形越小，且当胶层厚度一定时，蜂窝的热变形占主导因素，其刚度变化值提升2倍时影响趋势突变，此时蒙皮刚度对蜂窝热变形的抑制作用明显，当蜂窝的CTE改变11倍时，反射器热变形RMS改变值大于80%。经试验测得环境温度由20℃降到-80℃时两种典型反射器的热变形的RMS值和仿真计算差值分别为15.7%和15.2%，证明仿真结果可靠，可通过优化相应的结构参数为星载天线反射器的设计提供参考。 To explore the main self-structure factors affecting the thermal distortion of rigid antenna reflector in orbit, a spaceborne honeycomb sandwich structure model with a diameter of 1.2 m was analyzed. Firstly, by altering the skin material, the thickness of adhesive, the property include stiffness and coefficient of thermal expansion (CTE) of honeycomb, a finite element simulation software was used to calculate the root mean square (RMS) of the thermal deformation of the reflector when the ambient temperature changes from 20℃ to -80℃. Furthermore, the causes of each factor were analyzed. Secondly, two typical honeycomb sandwich structure reflectors of M55J and T300 skin materials were prepared by autoclave molding process so as to validate simulation results. The results indicate that the thermal deformation of the M55J skin material reflector is smaller than that of the T300. In addition, there is a linear relationship between the thermal distortion and the thickness of the adhesive, the thinner the later, the smaller the former. When the thickness of the adhesive layer is constant, the thermal deformation of the honeycomb is the dominant factor. The effect of the skin stiffness on the thermal deformation of honeycomb is obvious as the increasment of the stiffness value is 2 times. Moreover, when the normal CTE of honeycomb is changed by 11 times, the relative increment of thermal deformation is more than 80%. The thermal distortions of the two typical reflectors were measured as the environment temperature changed from 20℃ to -80℃. The difference of the thermal distortion between simulation and testing is 15.7% and 15.2%, respectively, which proves the simulation results are reliable. By optimizing the corresponding parameters can provide reference for the design of spaceborne antenna reflector. 国家自然科学基金青年科学基金项目（11503093）