Auxetic-Inspired Honeycomb Macrostructures With Anomalous Tailormade Thermal Expansion Properties Including “Negative” Heat-Shrinking Characteristics

Abstract

Negative thermal expansion (NTE) materials and structures exhibit the anomalous property of shrinking rather than expanding when heated. This work examines the potential of multi-material planar re-entrant and non-re-entrant honeycombs to exhibit anomalous thermal expansion properties. Expressions for the coefficient of thermal expansion as a function of the geometric parameters and intrinsic thermal expansion properties were derived for any in-plane direction. It was shown that re-entrant honeycombs, a metamaterial which is well known for its auxetic characteristics, can be made to exhibit NTE in specific directions when constructed from conventional positive thermal expansion (PTE) materials, provided that the slanting ligaments expand more than the vertical ligaments when heated and that the geometry is amenable. Conversely, it was shown that the construction of such honeycombs from NTE components will not necessarily result in a system which exhibits NTE in all directions. Furthermore, conditions which result in honeycombs demonstrating zero thermal expansion (ZTE) coefficients in specific directions were also explored.

Enhancing the Mechanical Properties of Auxetic Metamaterials by Incorporating Nonrectangular Cross Sections into Their Component Rods: A Finite Element Analysis

“…[ 6–8 ] In addition to examining structures with negative PR, researchers have also paid attention to designing metamaterials with negative thermal expansion. [ 9,10 ] Auxetic materials of different scales, from molecular structures [ 11 ] to macroscale configurations, [ 12,13 ] have been investigated, thus confirming their applicability in various areas. [ 14 ]…”

Modeling Wear and Friction Regimes on Ceramic Materials with Positive and Negative Thermal Expansion

“…Additionally, this is an important task of modern material science. Tuning the CTE is a task that could be resolved by adjusting the composite structure [14] by developing material cellular architecture (metamaterials) that allows for the achievement of zero or even negative thermal expansion [15][16][17][18].…”