空间超高频遥感反射器热变形优化及零膨胀材料的制备

Optimization of thermal deformation of ultrahigh frequency remote sensing reflector and manufacture of a zero-expansion composite

空间超高频遥感反射器(工作频段600GHz以上)在轨运行过程中,由于空间温度变化不均匀会产生热变形问题。为了保证反射面的电气性能,空间超高频遥感反射器要求反射面的型面精度均方差值r≤10μm。本文创新性地提出了一种单曲面板栅格结构反射器,利用有限元仿真分析软件对反射器进行热变形分析。研究了反射器的不同结构参数对反射面热变形的影响,并以低热变形为原则对反射器结构参数进行优化。优化后的结果仍然不能满足空间超高频遥感反射器的型面精度要求,因此设计并制备了一种热膨胀系数α≤0.5×10-7℃-1的零膨胀材料。这种零膨胀材料是将碳纤维增强聚合物基复合材料(CFRP)与芳纶(Kevlar)纤维织物按照一定比例交错循环铺层,利用该比例调整反射器层压板铺层,可以使反射面热变形降低至7.94μm,满足空间超高频遥感反射器的型面精度要求。

Space ultrahigh frequency remote sensing reflectors(above 600 GHz in operating frequency range)will cause thermal deformation problems due to non-uniform spatial temperature changes during orbital operation.In order to ensure the electrical performance of the reflecting surface,the space ultrahigh frequency remote sensing reflector requires the surface accuracy of the reflecting surface to have a root mean square of r ≤ 10 μm.Therefore,a novel single-panel grid structure reflector was innovatively proposed,and the thermal deformation analysis of the reflector was performed using finite element analysis software.The influence of different structural parameters of the reflector on the thermal deformation of the reflector was studied,and the structural parameters of the reflector were optimized based on the principle of low thermal deformation.The optimized results still couldn't meet the surface accuracy requirements of space ultrahigh frequency remote sensing reflectors.Therefore,a zero-expansion composite with coefficient of thermal expansion α≤ 0.5×10^-7℃^-1 was designed and manufactured.The zero-expansion composite is combined with carbon fiber reinforced polymer composites(CFRP)and Kevlar fiber fabric interlaced and layered in a certain ratio.By adjusting the ratio of reflecting surface laminates,the thermal deformation of the reflecting surface can be reduced to 7.94 μm to meet the surface accuracy requirements of ultrahigh frequency remote sensing reflector.