Structure performance analysis for TMT teritiary mirror system

TMT Tertiary Mirror System (M3S) is required to be able to track and point. It should rotate with the observing object. In this article, the schemes of Tertiary Mirror supporting assembly and position assembly are introduced. Then, the static and dynamic performance of Tertiary Mirror System has been analyzed. It is shown that, the maximum deflection is 1.024 mm, the maximum stress is 138.91MPa when gravity is affecting. The security of M3S can be assured when telescope is working at all required positions. The first nature frequency is 15.39Hz, the requirement 15 Hz has been satisfied. In addition, the response to earthquake has been estimated primarily. Results shows that when earthquake with mean return time 200 year happens in three directions simultaneous, or earthquake with mean return time 1000 years happens, the lateral support will be destroyed. Protection measures should be considered. Conclusions in this article are useful guides for the M3S design. 2014 SPIE.