An adaptive primary mirror design containing four mirror segments and 56 push-pull actuators is examined for optical correction capability and compatibility with control system dynamics. To perform this analysis and design effort, a finite element model of a primary mirror, its backup structure, a set of tangent bars, and 14 actuators was developed. Influence functions were obtained for motion at the various actuator armature locations. To satisfy dynamic control bandwidth requirements, a mirror modal frequency of 32 Hz (approximately one magnitude higher than the required bandwidth) had to be met for the structural system modelled with unpowered actuators. This paper details the finite element model and model results, as well as addresses the residual error resulting from a best static fit to various aberrations utilizing the influence functions.
D L Niemiec,
"Structural Analysis Of An Adaptive Primary Mirror", Proc. SPIE 0450, Structural Mechanics of Optical Systems I, (5 January 1984); doi: 10.1117/12.939277; https://doi.org/10.1117/12.939277