Cabras Luigi, Brun Michele, Misseroni Diego
Dipartimento di Ingegneria Meccanica e Industriale, Universitá di Brescia, via Branze 38, Brescia, 25123, Italy.
Dipartimento di Ingegneria Meccanica, Chimica e dei Materiali, Universitá di Cagliari, via Marengo 2, Cagliari, 09123, Italy.
Proc Math Phys Eng Sci. 2019 Dec;475(2232):20190468. doi: 10.1098/rspa.2019.0468. Epub 2019 Dec 18.
A challenge in nano- and micro-mechanics is the realization of innovative materials exploiting auxetic behaviour to tailor thermal expansion properties. For this purpose, a new class of micro-structured media possessing an extremely wide range of tunable (positive, negative or even zero) thermal expansion is proposed and analytically and experimentally assessed. For this class of isotropic media, the effective coefficient of thermal expansion is explicitly linked to two microstructural variables via a simple relation, allowing the design with desired values. The theoretical predictions for the negative thermal properties are fully validated by the experimental and numerical outcomes. The simplicity of the proposed structure makes the design useful for the production of a new generation of advanced media, with applications ranging from micromechanical devices to large civil and space structures.
纳米和微机械领域面临的一个挑战是如何实现利用负泊松比行为来定制热膨胀特性的创新材料。为此，提出了一类新型的微结构介质，其具有极其广泛的可调（正、负甚至零）热膨胀范围，并进行了分析和实验评估。对于这类各向同性介质，热膨胀有效系数通过一个简单的关系与两个微观结构变量明确相关，从而能够设计出具有所需值的材料。负热特性的理论预测得到了实验和数值结果的充分验证。所提出结构的简单性使得该设计对于新一代先进介质的生产很有用，其应用范围从微机械设备到大型土木和空间结构。
