Flexible support structure based on spring principle for a high precision reflecting mirror

摘要

A new type of three-leaf flexible structure based on the principle of spring is designed for high precision support structure of reflecting mirror which is under multi-working conditions (0 degrees and 90 degrees) in the optical inspection system of the on-orbit assembly space telescope validation prototype. Firstly, the external load and its action mechanism which can affect the surface figure accuracy and rigid body displacement are demonstrated; Secondly, the detailed structural form of the new flexible structure is given, and on the basis of this new structural form, the stress release principle and the theoretical analysis of the support stiffness are carried out; Finally, the finite element analysis method is used to optimize the size parameters of the flexible structure. The design results show that under the gravity load and the thermal load of +/- 2 degrees C, surface figure error caused by supporting structure is 4.5nm, the maximum translational displacement is 0.0073mm, and the maximum angular displacement is 1.22 ''.The test results show that the surface figure accuracy is better than lambda / 60 (lambda = 632.8nm), and the displacement of the rigid body meets the requirements of 0.01mm and 1.5 ''.