In this study, we present a novel topology-optimized design of a two-dimensional cavity-free mechanical metamaterial with a negative coefficient of thermal expansion. We challenge the prevailing hypothesis that cavities are necessary for achieving negative coefficients of thermal expansion. The proposed metamaterial is a periodic lattice of a topology-optimized unit cell comprising three distinct solid materials, analyzed using a homogenization method. To confirm the negative thermal expansion of the optimized structures, we present some numerical experiments of the optimized designs and analyze the deformation of the metamaterial under temperature variations.

中文翻译：

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表现出负热膨胀的无腔机械超材料的优化设计


在这项研究中，我们提出了一种具有负热膨胀系数的二维无腔机械超材料的新型拓扑优化设计。我们挑战了流行的假设，即空腔是实现负热膨胀系数所必需的。所提出的超材料是拓扑优化晶胞的周期性晶格，由三种不同的固体材料组成，使用均质化方法进行分析。为了确认优化结构的负热膨胀，我们提出了优化设计的一些数值实验，并分析了超材料在温度变化下的变形。