TMT telescope structure system: seismic analysis and design

This paper documents the methods used for the seismic design and analysis of the Thirty Meter Telescope (TMT) 2 . The seismic analysis includes response spectrum and nonlinear time history methods. Several seismic restraint design options are considered, both linear and nonlinear, and the seismic performance is presented for these options. The paper addresses several issues specific to large optical telescope seismic design and analysis: generation of appropriate response spectra and time histories; use of operational and survival level earthquakes; selection of damping coefficients; use of reduced degree of freedom models and their calibration with more detailed models; and local response spectra for telescope-mounted systems.