Modeling and Simulation of Chinese SONG Telescope

Abstract

Telescope structure is used to support and position the optical mirrors in the right place during the period of telescope observation, so it will have such capability to withstand a certain load. In order to ensure SONG telescope has such capability, FEM analysis and calculation are finished in this paper. With the help of ANSYS, firstly the finite element model of SONG telescope is built. Then using this model, the analysis and calculation of static and dynamic are performed, including the deformation under the gravity load with the tube in different directions, eigenfrequency calculation of the whole system and the responses under the seismic acceleration spectra. The results show that the max. offsets and max. relative tilt angles between primary mirror and secondary mirror are very little under the gravity load. The first natural frequency is 20.083Hz, larger than the design requirement 8Hz. The results of seismic load analysis show that the deformation in the telescope structure is 0.42mm and the stress is 33.8MPa, less than the allowable stress of the structure material. The above analyses verified that the structure design of SONG telescope is reliable and acceptable.