Low Thermal Expansion Machine Frame Designs Using Lattice Structures

• Published in: Applied sciences 2021-10, Vol.11 (19), p.9135
• Main Authors: Juasiripukdee, Poom, Maskery, Ian, Ashcroft, Ian, Leach, Richard
• Format: Article
• Language: English
• Subjects: additive manufacturing; Cellular structure; coefficient of thermal expansion; Design optimization; Design techniques; finite element analysis; Finite element method; Geometry; Laboratories; Lattice design; lattice structure; Manufacturing; Materials selection; Mathematical models; Mechanical properties; metrology frame; Molecular weight; Numerical models; Nylon 12; Polyethylene; Porous materials; Stainless steel; Thermal expansion; Ultra high molecular weight polyethylene
• ISSN: 2076-3417; 2076-3417
• DOI: 10.3390/app11199135

In this work, we investigated tessellating cellular (or lattice) structures for use in a low thermal expansion machine frame. We proposed a concept for a lattice structure with tailorable effective coefficient of thermal expansion (CTE). The design is an assembly of two parts: a lattice outer part and a cylindrical inner part, which are made of homogenous materials with different positive CTEs. Several lattice design variations were investigated and their thermal and mechanical performance analysed using a finite element method. Our numerical models showed that a lattice design using Nylon 12 and ultra-high molecular weight polyethylene could yield an effective in-plane CTE of 1 × 10−9 K−1 (cf. 109 × 10−6 K−1 for solid Nylon 12). This paper showed that the combination of design optimisation and additive manufacturing can be used to achieve low CTE structures and, therefore, low thermal expansion machine frames of a few tens of centimetres in height.