光学系统主镜组件的轻量化设计及结构-热分析

根据某型卡塞格林系统主反射镜组件的设计要求,在遵循主镜支撑结构材料的线膨胀系数与主镜材料相匹配原则的基础上,采用有限元分析和参数优化设计相结合的方法,设计和分析了3套主镜组件方案.结果表明,在结构参数相同情况下,SiC主镜的静态、动态性能优于熔石英和K9主镜.对SiC主镜进行轻量化参数优化后,得到了直径为256 mm、质量仅为1.22 kg的镜体.通过对3种方案主镜组件的结构-热分析表明,主镜及其支撑结构均采用SiC材料的第3种主镜组件方案,消除了材料间的热膨胀错配,主镜面的变形误差完全满足设计要求,综合性能优于其它两种方案.

Lightweight Design and Structure/Thermal Analysis of Primary Mirror Assembly in Optical System

According to the design requirement of a certain primary mirror assembly in Cassegrain system,based on the principle that the thermal expansion coefficient of the support structure should match with that of the mirror,three primary mirror assembly schemes are designed and analyzed by finite dement analysis and parameter optimization method. The results show that with the same structural parameters the SiC mirror has the better static and dynamic properties than the fused silica mirror and the K9 mirror. After the lightweight structure optimization,the mass of the SiC mirror with 256 mm aperture is only 1.22 kg, The structure/thermal analysis of the three schemes indicate that the third scheme,where both of the mirror and the support structure in the primary mirror assembly are made by the SiC material,has the better over-all properties than that of the other schemes, Moreover,the thermal expansion mismatch between the materials can be eliminated,and the SiC mirror surface is satisfactory with the design requirements in the third scheme.