CO_2探测仪反射镜组件设计

为了降低重力、力学试验、发射条件以及因材料线胀系数差异导致的热变形对CO_2探测仪反射镜面形产生的影响,从反射镜组件材料选择、结构设计和配合方式几个方面进行了分析。采用SiC材料制作反射镜,结合反射镜的环形支撑方式,通过有限元分析对镜体进行轻量化设计。选取线胀系数较小的殷钢材料,利用三角形结构的稳定性和双脚架柔性结构的灵活性设计出简易可靠的反射镜支撑结构。反射镜与支撑结构接触面为1∶50的锥度面,通过环氧树脂进行胶接。在严格的工艺条件控制下,对反射镜组件进行精密加工和装配。对反射镜组件进行力学试验测试,结果表明在X向、Y向、Z向的一阶频率分别为445,423和444 Hz,与有限元分析结果接近。试验后镜面面形变化量PV值小于1/10λ,RMS值小于1/30(λ=632.8nm)。证明了CO_2探测仪反射镜组件结构设计与装调的合理性,满足空间高光谱成像要求。

Design of mirror subassembly in CO2 sounder

To lower the impact of thermal deformation due to gravity,mechanical test,launching environment and linear expansion coefficient difference of the material on mirror surface of the CO2 sounder,an analysis was conducted in material selection,structural design and cooperation mode of the mirror subassembly.In the analysis,SiC material was adopted for mirror making,and light weight design was carried out in the mirror body through finite element analysis based on ring-shaped support mode of the mirror;then invar materials with relatively small liner expansion coefficient were selected to design simple and reliable mirror support structure based on stability of the triangle structure and flexible structure of the bipod;the mirror and support structure formed a 1 ∶ 50 taper surface through epoxy resin adhesive.Then in strict process conditions,precise machining and assembly and mechanical test were conducted in the mirror subassembly.The results show that primary frequencies in the X direction,Y direction and Z direction are respectively 445 Hz,423 Hz and 444 Hz,approximate to results from the finite element analysis.After such test,the mirror surface shape variation PV is lower than 1/10λ,with a RMS value lower than 1/30λ (λ=632.8 nm).It proves that structural design and adjustment of the CO2 sounder mirror subassembly,which are reasonable,can meet the requirements of imaging spectrometer.