Open AccessEquivalent thin-plate method for stressed mirror polishing of an off-axis aspheric silicon carbide lightweight mirror
Author(s) -
Liqi Yi,
Xuejun Zhang,
Haitian Hu,
Zhe Zhang,
Xuefeng Zeng,
Xiao Luo,
Desheng Xue,
Ge Zhang
Publication year - 2020
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.410759
Subject(s) - polishing , materials science , optics , deflection (physics) , silicon carbide , isotropy , residual stress , composite material , physics
No physical model of stressed mirror polishing, based on the small deflection and deformation of elastic thin plates, has been applied in processing lightweight mirrors. We propose an equivalent thin-plate method for the stressed loading of lightweight mirrors for the first time. Stressed loading and polishing of an aspheric lightweight mirror are simulated using the small-deflection deformation theory of an elastic thin plate. We simulate off-axis aspheric silicon carbide (SiC) lightweight mirrors with three different structures, determining the corresponding equivalent thickness plate in a lightweight structure with a nearly uniform surface density distribution and isotropic bending properties. We then establish a residual removal model of a stressed polishing surface, design the stressed loading equipment, and propose an iterative method for stressed polishing of an off-axis aspheric SiC lightweight mirror. The results demonstrate that it is feasible to choose a lightweight structure that performs full-aperture stressed polishing on off-axis aspheric lightweight mirrors consisting of SiC or other materials.