【摘要】 为了消除自重和热应力对大口径平面反射镜面形精度的影响,采用有限元分析方法,对比分析了在-20℃环境温度下采用背部固定约束与背部浮动约束获得的反射镜面形仿真数据,设计了动态扫描反射镜背部悬浮支撑结构以实现浮动约束,搭建了检测平台,并进行了大口径平面反射镜面形检测。结果表明,安装该支撑结构后反射镜的面形峰谷值为0.236λ,平均值为0.049λ。背部悬浮支撑结构实现了浮动约束,释放了大口径平面反射镜因自重和热应力造成的变形,有效保证了面形精度。更多还原

【Abstract】 For eliminating the effects of weight and thermal stress on the surface accuracy of a large flat mirror,the surface accuracy was analyzed for the back fixed constraint and the back float constraint structures at- 20℃ by means of the finite element method. The design of support structure using finite element method was studied. By using the back fixed constraint and the float constraint at- 20℃,the simulation data of mirror surface accuracy was obtained and analyzed comparatively. The back suspension support structure for dynamic scanning mirrors was designed to achieve the back float constraint. After the establishment of detection platform,the profile of the large flat mirror was measured. The results show that the values of peak-to-valley and root mean square of the flat mirror with back suspension support structure were 0. 236λand 0. 049λ respectively. The back suspension support structure could achieve float constraint and release the surface shape deformation of large flat mirrors caused by weight and thermal stress and ensure the surface accuracy effectively.更多还原