Structural Response of Extremely Large Telescopes

This paper is concerned with the extrapolation of the dynamic response of the primary mirror of current 10-meter class telescopes to the next generation of 30 to 40 m extremely large telescopes and future, even larger, ones. A numerical study is conducted on a family of primary mirrors of increasing size, and the results are compared with analytical scaling laws derived earlier from a much simpler analysis. The correlation between the numerical and the analytical results is quite good and, to a large extent, independent of the boundary conditions. This confirms that the analytical scaling laws can be used in confidence to conduct parametric studies in the preliminary design phase of extremely large segmented mirrors.