Design of hourglass-lattice metastructure with near-zero thermal expansion using structural optimization method. (15th February 2023)

• Record Type: Journal Article
• Authors: Xu, Zhao; Zhao, Haifeng; Wang, Ke
• Is Part Of: Engineering structures. Volume 277(2023)
• Publication Date: 2023-02-15
• Subjects: Near-zero thermal expansion (near-ZTE) -- Negative thermal expansion (NTE) -- Structural optimization -- Multilayered metastructure -- Hourglass lattice with variable cross-sectional and bi-material beams; Structural engineering -- Periodicals; Structural analysis (Engineering) -- Periodicals; Construction, Technique de la -- Périodiques; Génie parasismique -- Périodiques; Pression du vent -- Périodiques; Earthquake engineering; Structural engineering; Wind-pressure; Periodicals; 624.105
• DOI: 10.1016/j.engstruct.2022.115374
• Languages: English
• ISSNs: 0141-0296

Abstract

Highlights: Sandwich panels of hourglass-type lattice metastructure are designed with near-zero thermal expansion; Lattice cells with variable cross-sectional bi-material beams are optimized with structural optimization scheme to possess tunable positive or negative thermal expansion; Multilayer lattice structures integrated with positive and negative thermal expansion cells possess ultra-low coefficient of thermal expansion (∼10 -9 /K); The experiment with an additive-manufactured prototype agrees well with the numerical result. Abstract: Zero thermal expansion (ZTE) is strongly demanded for critical components of spacecraft structures exposed to extreme temperature variations in space. In this paper, a lattice metastructure with near-ZTE is numerically achieved by structural optimization method. A sandwich panel with one single layer of hourglass-type lattice cells with variable cross-sectional and bi-material beams are assembled to produce either positive or negative thermal expansion (PTE or NTE). Then, a multilayered construction of metastructures is proposed by the combination of both PTE and NTE layers to realize the overall behaviors of near-zero deformation. The structural optimization with the gradient-based algorithm is utilized to obtain an extreme low value of coefficient of thermal expansion (∼10 -9 /K). The shape constraint is adopted to regulate the thermal deformation of contact surfaces of each layer. Furthermore, bi-material prototypes with nylon and short carbon fiber reinforced composites are fabricated and tested, and the results demonstrate a NTE value of −6.32 × 10 -5 /K, PTE value of + 1.28 × 10 -4 /K, and ZTE value of 2.53 × 10 -6 /K. This agrees well with the optimization result. Overall, the proposed hourglass-lattice metastructure with a high thermal stability is a promising solution to enable large-scale space structures such as space telescope, antenna, and radar, etc.