Design and verification of a silicon carbide special-shaped mirror set based on 3D printing

Abstract

As an important optical component, the mirror is an important part of the tracking camera. The rapid prototyping technology of 3D printing is becoming more and more mature, and its application scope is more and more extensive. Silicon carbide material has excellent physical properties such as high elastic modulus, specific stiffness and thermal stability. To meet the practical requirements of high stiffness, light weight of a special-shaped mirror, topology optimization was adopted to design the mirror structure. The objective is maximizing the weighted superposition of the structural stiffness and the first-order natural frequency；the constraint function is an upper bound on the volume fraction. After optimized design, the mirror with a special shape back was obtained. A feasible CAD model was formed by adjusting the position and thickness of the stiffener. The self-weight deformation and natural frequency of the model were analyzed by commercial finite element analysis software and the results show that the maximum RMS value of the mirror under 1g gravity condition is 14.6nm, and the first-order natural frequency is 2037Hz. Then the 3D printing additive manufacturing technology was used to fabricate the special-shaped mirror. After adjusting ,when the optical axis of the mirror and the ground into an Angle of -40°, 0°, 40°and 80°, the mirror surface accuracy meets the requirements.