为了解决CFRP(carbon fiber reinforced polymer)平面反射镜在加工成型后的面形存在像散像差的问题, 建立相关的理论模型以对其产生机理进行解释, 并设计实验对模型进行验证。首先基于经典层合板的热效应理论, 考虑到CFRP平面反射镜制造过程中存在铺层角度误差及温度变化等因素, 推导了相关公式以说明当对称均衡铺层CFRP反射镜存在铺层角度误差时, 在热效应的影响下会产生马鞍形的变形, 即会导致面形出现像散像差。设计了相关实验, 制备了两组铺层角度分别为[0° 90° 45° -45°]2s和[(0° 90° 45° -45°)s]2的反射镜样片, 并利用Zygo长波红外干涉仪(λ=10.6 μm)对样片总体面形及像散像差进行检测。实验数据显示: 第一组样片像散像差的RMS值平均为0.034λ, 第二组样片像散像差的RMS值平均为0.510λ。证明了铺层角度误差是使反射镜产生像散像差的主要原因之一, 而且像差大小会随着反射镜弯曲刚度准各向同性的提高而减小。

In order to solve the problem that there exists astigmatism during the fabrication of carbon fiber reinforced polymer(CFRP) reflective mirror, a theoretical model was established to explain the relations, and relative experiments were made to verify the model. First, from classical laminate thermal effect theory, ply angle misalignment and temperature variation during manufacturing process were considered. The corresponding formulas were deduced to demonstrate that the surface of CFRP reflective mirror existed astigmatism under thermal effect because of ply angle misalignment. Two groups of samples with respective ply sequence [0° 90° 45° -45°]2s and [(0° 90° 45° -45°)s]2 were manufactured and their astigmatism were measured with a Zygo long-wave infrared interferometer(λ=10.6 μm). Experimental results indicate that average astigmatism RMS of the front group is 0.034λ, and average astigmatism RMS of the latter group is 0.510λ. It verifies that one of the main reasons causing astigmatism of CFRP reflective mirror is ply angle misalignment, and the degree of astigmatism will decrease by increasing quasi-isotropy of bending stiffness.