【作者】 黄启泰；

【导师】 余景池；

【作者基本信息】 苏州大学 ， 光学工程， 2004， 硕士

【摘要】 随着空间光学技术的发展，人们对空间相机主反射镜提出了口径更大的要求。反射镜口径增加带来的主要技术问题有：反射镜因自重而引起的镜面变形增大，反射镜因环境温度变化及镜体温度梯度而产生的镜面热膨胀变形增大。同时为降低发射成本，主反射镜必须轻量化，而轻量化后在重力作用下的变形也将加剧，这种变形将直接影响相机的成像效果，也将影响反射镜的加工和检测。因此减小自重变形的影响成为一个重要课题。 本文介绍了目前国内外关于该课题的研究现状，并根据实际的工程需要采用碳化硅作为主镜材料，选择了适当的轻量化形式对主镜的支撑方案进行了讨论研究。讨论了对主镜进行面形分析所需要满足的力学条件，根据实际情况设定了边界条件，并采用当前常用的有限元方法对主镜的支撑方案进行面形变形的分析，以得到在相同的支撑条件下主镜水平放置和竖直放置时均能符合面形要求的支撑方案，并对支撑方案进行优化。 在对镜面变形的结果进行数据处理时采用了最小二乘法，根据最小二乘原理编制了一个适用于Patran所提供数据形式的程序对镜面的零散数据进行处理，得到镜面的PV和RMS值。 最终的分析数据表明，本文所讨论的支撑方案设计可以满足实际的工程要求，即在两种工况下主镜面形变化的均方差均在λ／60(λ=632.8nm)之内。更多还原

【Abstract】 With the development of space optical technology, there exits higher demands for the larger-diameter primary mirror for the space usage. Increasing in diameter, however, lead to the following technological problems: the distortion caused by deadweight of mirror will increase, and the heat-swell distortion of the mirror face due to the change of the environment temperature and the mirror grads will increase too. At the same time, the primary mirror should be light-weighted to reduce the launch cost. But the distortion will increase even more under gravity after this process, which, in turn, will directly affect image quality of the space mirror, as well as the machining and the checking. Consequently, how to minimize the deadweight distortion becomes an important subject for research.The thesis makes a brief introduction to the recent research within this field. Then, according to the actual project requirement, SiC is chosen as the material for the primary mirror, and a proper form of lightweight is selected for support structure analysis as well. The mechanical conditions satisfied for the mirror face distortion are discussed at first. Then, with borderline condition set for actual condition. We designed a same support structure under two different cases, horizontally and vertically. The finite element method (FEM) is employed to carry out the support structure analysis of the primary mirror. With the cause of distortion obtained from the analysis, the support structure is optimized accordingly.7y using the least square method, the data of the distortion of the mirror surface are analyzed. A specific program is compiled to deal with Patran data, and PV and RMS figures are gained from the calculation.The final constructed data indicate that the support structure discussed in the thesis satisfies the actual project request, since the RMS criteria under two operating modes for the change of the mirror surface are both within the range of X/60 (X=632.8nm) .更多还原