展开式反射镜单元镜支撑技术

基于展开镜结构工作原理,运用有限元方法分析了展开式反射镜单元的裸镜及其支撑方案.目的是确定镜子支撑点数量及排布方式,并具体分析了12-6-1、12-8-1和16-8-1型三种支撑点排布方式,分别计算了各支撑点排布方式下的镜面自重变形.计算结果表明,采用16-8-1型的排布方式较为合理.支撑结构的优化设计是在裸镜支撑点优化位置加入支撑组件综合分析镜坯与支撑组件,以镜面面形误差及结构总体刚度为目标函数,考查、修改支撑组件以保证镜面RMS值在可调节范围(30μm)内.计算带有支撑组件的单元反射镜在自重作用下的变形,得出的镜面RMS值为16.52nm,小于1/4波长(632.8nm),表明将该支撑方案应用于单元镜具有可行性.并提高整个反射镜面的面形质量.

Support technique of a deployable unit mirror

Based on the deployable structure of a mirror and the operation principle,the finite element method was used to analyze the unit naked mirror and some different mirror support schemes. The principal aim of the naked mirror analysis is to get the numbers of the support points and the ways of the support. There are three schemes including 12-6-1,12-8-1 and 16-8-1 models. Deformation of the deadweight is calculated under the three conditions. The way of 16-8-1 is more suitable than the designs of other two. The optimum design of the support structure is based on the surface figure error and the structure rigidity. Support subassembly is amended to meet with the mirror surface RMS in the range of 30 μm.Deformation of the mirror with support structure has been calculated. The result is 16.52 nm,lower than a quarter of the wavelength,which indicates the feasibility of the support scheme applied to unit mirror.