Etude par éléments finis des performances mécanique de différentes architectures de miroirs légers en nid d'abeille pour les télescopes

Abstract

With the current and future challenges of astronomy and astrophysics, two sciences based mainly on remote observation, the primary mirrors of ground and space telescopes continue to grow. Indeed, in order to improve the resolution and sensitivity of telescopes, they must have large openings and therefore primary mirrors of large diameters. For telescopes operating in orbit, this poses problems of cost, and also the capacity of the launchers with regard to mass and limited volume In order to control these problems, the mirrors must be lightened as much as possible while maintaining a certain rigidity so that they can keep their optical surfaces within the prescribed tolerances. The mirror architecture with cellular cores is one of the most widespread and widely used architectures for the lightening of mirrors, This kind of mirrors consists of a cellular core, usually honeycomb, above which is a thin face with the optical surface on it and in some cases a back face (case of sandwich mirrors). These telescope mirrors are made on earth. When they arrive in orbit, they already undergo deformations because of the cessation of the action of Earth's gravity. Our work will focus on this deformation, and we will study it using the finite element method according to several architectural parameters, and related to materials in order to see the effect of each parameter on the performance of mirrors in weightlessness