对采用圆锥嵌套Wolter-I型结构的X射线聚焦望远镜在装配过程中产生的面形偏差进行了模拟和分析。首先, 利用ANSYS有限元软件建立二维模型。然后, 以实际装配步骤和夹具为加载和边界条件, 通过分析不同半径镜片的装配过程, 得到了面形偏差与三根压条的载荷关系曲线, 由此优选出了不同半径镜片对应的最佳装配载荷。分析显示: 除对应的最大面形偏差外, 优选出的装配载荷均可控制在0.1 μm以内, 满足装配精度要求, 而且对应装配载荷下玻璃镜片的最大Mises应力也均小于玻璃的强度极限, 不会在装配过程中失效。此外, 建立了三维分析模型并与二维简化模型分析结果进行了比较。结果显示: 计算偏差主要集中在镜片的前、后两端约5 mm范围内, 最大偏差为2.3 μm; 镜片中段两种模型的计算偏差小于0.03 μm, 表明提出的二维简化模型可以用于玻璃镜片装配的快速面形偏差分析和载荷确定。文中对镜片装配过程的分析可为提高装配精度提供理论依据。

The surface errors in mounting process of a mirror used in the X-ray focusing telescope with a nested conical approximation Wolter-I type structure was simulated and analyzed for an X-ray Timing and Polarization (XTP) satellite. Firstly, the 2-D finite element model was established based on ANSYS. Then, by taking the actual jig and mounting process as loading and boundary conditions, the curvilinear relationship between surface error and loading on three bars was obtained through the analysis of mounting process of the mirror with different radii and the optimized loadings according to different mirrors were selected. Analysis results show that the minimum surface error is less than 0.1 μm according to the optimized loading and satisfies the accuracy requirement. Moreover, the maximum stresses in the mirror are less than the ultimate strength of glass and maintain the reliability in mounting process. A 3-D model was established to compare with the 2-D model for deviation analysis. Results show that the main calculating deviation is 2.3 μm at front and back sections of the mirror in length about 5 mm. The calculating deviation at middle of mirror is less than 0.03 μm. The research show that the 2-D model could be used in the fast surface error analysis and loading confirmation. According to the analysis of mirror mounting process, the accurate mechanics analysis could provide academic bases and references for improving mounting accuracy.