Design And Analysis For The Support Structure Of Large Aperture Rectangular Mirror

Telescope is widely used in astronomy observation, natural resources research,meteor forecast and outer space explore. With the development of science andtechnology, the requiement of resolution become harsher and harsher, the diameter ofthe reflector has to be amplified to satisfy these imaging quality and parameter. But withthe diameter of the reflector becomes biger, the distortion of the optical surface undergravity become more serious, the optical surface become more sensitive to thermaldifferrence. Reflector is telescope’s key component, its imaging quality is deeply dependon the quality of the reflector’s surport structure.In this paper, the theory analysis, schematic design and specific structure about thereflector’s support system has been design and analysised. After the engineering analysisof the support system influenced by gravity and tempereture, critical factor thatinfluenced the optical surface has been fond out, corrective actions has been put forward;the primary coverage include:1. conbined with thin plat theory and curcular plat axis symmetrical bending theory,general problem and their corresponding corrective actions has been analysed andsummarized.2. The factors influence the surface quality of reflector has been analysised, theregularity and relationship about different structure shape of main reflector has beenresearched and summarized.3. Some critical technology about surface distortion data operation has beenresearched and realized, espacially studied on the Zernike polymerizaton fitting,realized the special system for reflector’s support structure design based on thesecondary development of ANSYS and mutual call between ANSYS and MATLAB.The algorithm has been researched and program codes has been generated. With thissystem, the support parameters optimal rate and quality has been distinct raisedcompared with traditional experiential design.4. With the upper grondwork, a support stucture of a rectangular reflector has beendesigned, the support parameters has been optimized with the special system. A specialshperical hinge flexible six rods support structure has been designed and analysised onits kinematics and statics theory.The structure model is designed by Inventor software, engneering analysis hasbeen proceeded with ANSYS. The analysis result illustrates that the surface distortion RMS=28.9nm, well satisfied the design requirment that distortion under gravity and30℃thermal difference less thanλ/20(λ=632.8nm).