Optical mirrors design using topology optimization for additive manufacturing (Conference Presentation)

OPTICAL MIRRORS DESIGN USING TOPOLOGY OPTIMIZATION FOR ADDITIVE MANUFACTURING (ABSTRACT) Author : Nisrine Louh1 Co-authors : Malorie Villemaire1, Stephanie Behar Lafenetre1, Nicolas Rousselet2, Vincent Costes3 Contact : Nisrine Louh – nisrine.louh@thalesaleniaspace.com 1. Thales Alenia Space, 5 Allee des Gabians, 06150 Cannes, France 2. 3D Ceram, Limoges 3. CNES Themes – Mirrors, topology optimization, space structures, additive manufacturing For scientific satellite, the mirrors are always on the critical path of a project. The design and the sizing of the mirrors are constrained by the mechanical holding, the mass, the cost and the manufacturability. These criteria require numerous compromises and therefore, optical mirrors are designed as early as possible to anticipate the leanings, the manufacturing time and the risks during this manufacture. In this article, we will describe a new method developed to optimize the space optics taking into account the various specifications and using topology optimization. This development is settled in the perimeter of a CNES study named FAME in collaboration with 3DCERAM. The goal is to highlight the feasibility and interest to “print” a telescope mirror. Our objective is to define a way to reduce the weight, to avoid deformation of the optical surface and at the same time to keep a stiffness that allows the structure to withstand the vibration loads. Moreover, this new approach permits very innovative designs. First, the optimization is made on both the mass and the stiffness. Then, mechanical analyses are performed to verify that the design is viable on the mechanical environment of the mirror. Besides, we verify that the Wavefront Error and the optical performances are compliant with our needs and requirements. Thales Alenia Space is interested in studying and introducing additive manufacturing in its processes. The advantages and limits of this new technology to “print” complex designs are presented.