摘要
为了提高轻小型碳化硅反射镜的面形精度并减轻其加工成本,针对某空间相机的Φ210mm SiC反射镜进行超轻量化设计.采用背部三点支撑并优化支撑点的位置,通过拓扑优化,得到反射镜背部需保留和可去除材料的分布情况.结合背部开放式、三角形孔的轻量化方案,确定反射镜轻量化结构的初始模型.应用多目标集成优化方法,建立以反射镜重量和X向自重工况面形为目标,Z向自重工况面形值为约束的优化模型,对该反射镜进行了优化设计.优化后反射镜的X向自重工况下RMS值仅为0.18nm,Z向自重工况下RMS值为2.38nm,重量仅为0.568kg,面密度达到16.9kg/m^2,X、Y、Z三向基频都在500Hz以上.本文设计的反射镜结构有良好的力学性能,本文优化设计方法是合理有效性.
This paper has proposed ultra-lightweight design and optimization for a primary mirror of a space camera with Φ210 mm aperture to improve surface quality and reduce its launching cost.Threepoint support on mirror back is selected as the support method and the locations of the supports are carefully studied.Through the topology optimization,the mass distribution of the back of the mirror and the distribution of the removable part are obtained.The initial structure of mirror is light weighted on its back applying triangular hole light-weighting method.Multiple-object optimization which combines mass and surface figure error along X-axis（detection direction）as optimization object under constraint of surface figure error along Z-axis（machine direction）is carried out on the initial structure of mirror.Finally,a mirror with RMS（Root Mean Square）as lowas 0.18 m with X-axis straight down and 2.38 mm with Z-axis straight down is achieved.The mirror weights 0.568 kg,surface density of it is as low as16.9 kg/m^2.And the primary frequency of X,Y,Zare more than 500 Hz.Through the FEM analysis and vibration test,verify the good mechanical properties of the mirror structure.The results show that the optimal design method of this paper is reasonable for the lightweight mirror.
出处
《光子学报》
EI
CAS
CSCD
北大核心
2017年第12期83-91,共9页
Acta Photonica Sinica
基金
国家重点研发计划(No.2016YFB0500904)资助~~
关键词
超轻量化
拓扑优化
多目标
集成优化
随机振动
Ultra-lightweight
Topology optimization
Multi-objective
Integrated optimization
Random vibration
