针对立式大口径平面干涉仪, 采用结合Zernike多项式的三平面互检面形检测方法, 研究参考平面在装夹情况下的自重变形对绝对面形检测结果的影响.运用ANSYS有限元分析方法研究了不同参数下的装夹和自重变形情况, 得到了最优的装夹参数为环带宽度15 mm、平面厚度90 mm, 此时的变形量峰谷值为0.023λ(λ=632.8 nm).通过参考平面装夹自重变形对测量结果影响的模拟检测试验和对比分析, 发现参考平面装夹自重变形不仅影响其自身的面形, 而且对未变形大口径平面的绝对面形检测结果也有较大影响, 面形残差峰谷值基本都在0.011λ, 尤其在高精度干涉测量中该影响不可忽略.研究结果可为高精度测量的变形补偿提供参考.

Aiming at the vertical large plane interferometer, the method of threeflat test with Zernike polynomials was used to study the influence of the clamping and gravity deformation of the large plane on the absolute surface test results. The method of ANSYS finite element analysis was used to simulate the clamping and gravity deformation under different parameters. The clamping parameters of the ring width of 15 mm and the plane thickness of 90 mm are optimized, and the deformation quantity peakvalley value is 0.023λ (λ=632.8 nm). The result of simulation experiment and comparative analysis base on the threeflat test with reference plane deformation show that the clamping and gravity deformation of the large reference plane in the vertical large plane interferometer is not only effects on the reference surface shape of the reference plane itself, but also affects the absolute surface shape of the large plane without deformation, and the surface deviation peakvalley value is basically 0.011λ, so the clamping and gravity deformation influence can′t be ignored. This study will provide references for future research on deformation compensation.v