长条形空间反射镜轻量化及其支撑结构设计

Lightweight and support design for rectangular space mirror

为保证空间反射镜在空间应用环境中保持高位置精度和面形精度,实现良好成像,从结构材料的选择、反射镜轻量化设计及支撑结构设计三个方面对某长条形空间反射镜进行了详细的结构设计。提出了一种底面局部开口、三角形加强筋的轻量化形式,反射镜采用背部三点支撑方案,通过合理设计柔性支撑结构参数,使反射镜保证了高刚度和热尺寸稳定性要求。采用有限元法对反射镜系统进行了静、动态特性和热特性分析。分析结果表明:自重及5℃均匀温变载荷工况下,反射镜面形精度达到λ/10 PV,λ/50 RMS(λ=632.8 nm);反射镜组件一阶固有频率230 Hz,具有足够高的动静态刚度和热尺寸稳定性,满足空间应用要求。

In order to meet the requirements of high location accuracy and surface figure accuracy for space mirror,material selection,lightweight pattern and the design of support were taken into account in the design of a rectangular space mirror.A new design with local open bottom,triangular hole light-weighting structure is proposed.Mirror with the back three-point support scheme,through the rational design of flexible support structure parameters is adopted to ensure high stiffness and thermal dimensional stability.By using finite element analysis（FEA）technique,the static and dynamic stiffness as well as thermal characteristics of the mirror component are analyzed.Analysis results indicate that the surface accuracy reach to λ/10 PV,λ/50 RMS（λ=632.8 nm）under gravity and 5 ℃ uniform temperature change,the first order natural frequency of the primary mirror component is 230 Hz,which can meet the requirements of space application.