Design and Fabrication of Extremely Lightweight Truss-Structured Metal Mirrors

Abstract

Three-dimensional printing, also called additive manufacturing (AM), offers a new vision for optical components in terms of weight reduction and strength improvement. A truss, which is a triangulated system of members that are structured and connected in such a way that they mainly bear axial force, is commonly used in steel structures to improve stiffness and reduce weight. Combining these two technologies, an extremely lightweight truss-structured mirror was proposed. First, the finite element analyses (FEA) on surface shape deviation and modal properties were carried out. Results showed that the mirrors had sufficient stiffness and a high weight reduction of up to 85%. In order to verify their performance, the truss-structured mirror blanks were fabricated with AM technology. After that, both the preprocessing and the postprocessing of the mirrors were carried out. The results show that without NiP coating, a surface shape deviation of 0.353λ (PV) and 0.028 λ (RMS) (λ = 632.8 nm) with a roughness of Ra 2.8 nm, could be achieved. Therefore, the truss-structured mirrors in this study have the characteristics of being extremely lightweight and having improved stiffness as well as strong temperature stability.

Design and Fabrication of an Additively Manufactured Aluminum Mirror with Compound Surfaces

“…Cooperating with LPBF, it is applicable for thin-walled components with complex geometries. LPBFed AlSi 10 Mg is highly suitable for processing and characterized by good resistance in corrosive atmospheres and high electrical conductivity [ 29 ]. The combination of high achievable strengths while maintaining dynamic load capacity enables it to be used for highly stressed parts.…”

Design and Mechanical Characterisation of a Large Truss Structure for Continuous Manufacturing in Space

“…The fold-and-spread process is somewhat limited as the truss size increases due to the space available to carry the rocket, the high cost of construction and low space utilization. In-space fabrication [ 7 , 8 , 9 , 10 , 11 ] is an inevitable trend in the construction of large space truss structures, i.e., the material is packaged for launch on the ground and fabricated for connection in space so that the continuous fabrication of truss structures is one of the necessary conditions for the construction of substantial structural dimensions.…”