Design And Performance Analysis Of Lightweight Structure Of Main Mirror Based On Finite Element Method

The primary mirror is a very important part of the optical termination system and serves to collect a variety of information.In order to improve the reflectivity of the primary mirror,with the development of space optical technology and the increasing demands on the field of view and imaging quality,it is an effective way to increase the aperture of the primary mirror.However,In addition to the increase in design and manufacturing costs,there are still many technical problems,including the structural design,material selection and support methods have a great impact on the final performance of the system,such as the static analysis of the primary mirror and thermodynamic analysis,The increase of large-diameter primary mirror will lead to increased deformation caused by increased self-weight,large temperature difference caused by the deformation of the mirror and increased self-weight caused by increased costs,so the primary mirror system must be lightweight structural design to ensure that the space environment Under the system performance of the stability.This paper introduces the research status of the large aperture primary mirror both at home and abroad.Through the study of the finite element method,the program of finite element modeling and analysis and the introduction and analysis of the various schemes of the light weight are confirmed.The 1m diameter Si C main The mirror as the research object analysis,through the analysis of silicon carbide as the main mirror material,obtained the appropriate lightweight form,the theoretical analysis of tetrahedral units.The lightweight structure of the large aperture primary mirror was designed with UG,and the performance of the lightweight structure was analyzed by finite element software,including static analysis and thermodynamic analysis.The theoretical analysis and data analysis of the advantages and disadvantages of lightweight holes in different working conditions,The lightweight structure is optimized by using the cloud structure of finite element analysis of lightweight structure,the performance of the primary mirror is ensured under the condition of ensuring the highest light-weight ratio,and the support mode of the primary mirror is analyzed,and finally the primary mirror The structure of high light weight and hexagonal lightweight hole flat back-shaped structure,theoretically determined the lightweight structural parameters,the primary mirror light weight rate of 90.3%,and the data provided to deal with the light Quantify the PV and RMS values of the primary mirror at different steady-state temperatures.Finally,the modal analysis of the four-wing cross-shaped secondary mirror,Including the first four natural frequencies and mode shapes,is made.Compared with the actual calculation of the first-order natural frequency of the secondary mirror,how to improve the first-order natural frequency of the secondary mirror system The optimization proposal is conducive to controlling the mirror deformation,which provides a reference for the lightweight design and optimization and improvement.