Engineering Analysis of Mirror Subassembly Based on Contact Algorithm

Linear analysis method is often used in engineering analysis of space-borne mirror subassemblies, thus big errors are usually existed in using linear method analyzing nonlinear systems. Obvious contact character exists in a certain type of mirror subassembly, so an analysis method based on contact theory was introduced in this paper. The comparative analysis of the mirror subassembly between the linear and nonlinear analysis method is made based on four load cases (gravity along with optical axis in different directions and the ±5°C uniform temperature change). The results indicate that the contact character and the surface accuracy changed with the changing of the load direction. But the change will not be shown in linear analysis results, while the contact algorithm can better simulate the real state of the mirror system. The surface accuracy of the mirror can reach and close to λ/10 P-V, λ/50 RMS (λ @632.8nm) under the four load cases. The first order natural frequency of the mirror subassembly is 543 Hz, the analysis results there is only 4.6% of error and can meet the requirements of the space application.