次镜支撑结构硬涂层阻尼减振设计与仿真

Design and simulation of hard coating damping vibration for secondary mirror support structure

为了提高大口径空间望远镜次镜支撑结构的动力学特性,获得更好的成像质量,在对比了目前减振方式优缺点的基础上,提出了一种将阻尼硬涂层涂覆在次镜支撑薄壁梁上进行减振的方法。首先以硬涂层-次镜支撑复合结构综合性能最优为目标分析了硬涂层的最佳涂覆厚度和弹性模量,然后在此基础上用ANSYS分析了次镜支撑结构涂覆硬涂层前后的加速度响应曲线,最后利用Zemax和Matlab等软件分别从镜片刚体位移和镜面面型变化两个角度分析了硬涂层减振对光学成像性能的影响。分析结果表明,在一个6 g量级的正弦激励作用下,涂覆硬涂层后次镜组件在X、Y、Z三个方向上的加速度响应较涂覆前均下降了30%~50%,光学系统成像质量和次镜面型精度也有很大提高。

In order to improve the dynamic characteristics of the secondary mirror support structure of a large aperture space telescope and obtain better imaging quality, a method of damping vibration by coating a hard damping coating on the thin-walled beam of the secondary mirror support was proposed based on the comparison of the advantages and disadvantages of the current methods. Firstly, the optimal coating thickness and elastic modulus of the hard coating were analyzed with the objective of optimizing the comprehensive performance of the hard coating and secondary mirror support composite structure. Then, the acceleration response curve of the secondary mirror support structure before and after the hard coating was analyzed with ANSYS. Finally, the effects of the hard coating on the optical imaging performance were analyzed by using Zemax and Matlab software respectively from the rigid body displacement and the mirror surface profile change. The analysis results show that the acceleration response of the secondary mirror assembly in X, Y and Z directions decreases by 30%to 50% compared with that before coating under a sinusoidal excitation of 6 g magnitude, and the imaging quality and the precision of the secondary mirror model of the optical system are also greatly improved.