Abstract Most metamaterials with negative Poisson’s ratio and/or negative thermal expansion coefficient possess relatively low stiffness. In this work, a novel hybrid-honeycomb structure with enhanced stiffness is proposed. It consists of two merged hexagonal honeycombs. Analytical and computational homogenization methods are used to evaluate the effective thermoelastic properties. Analytical expressions of the effective Young’s modulus, Poisson’s ratio, and thermal expansion coefficient are given. We show that the effective thermoelastic properties of the structure are widely tunable by tailoring the microstructural geometry and the constituent materials. In particular, the in-plane effective Poisson’s ratio and thermal expansion coefficient are adjustable over a wide range, from negative to positive. By properly choosing the geometrical and material parameters, the structure can be designed to concurrently possess an enhanced stiffness and a high degree of auxeticity and negative thermal expansion.

中文翻译：

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一种新型混合蜂窝结构：增强的刚度、可调节的拉胀和负热膨胀

摘要 大多数负泊松比和/或负热膨胀系数的超材料具有相对较低的刚度。在这项工作中，提出了一种具有增强刚度的新型混合蜂窝结构。它由两个合并的六边形蜂窝组成。分析和计算均质化方法用于评估有效的热弹性特性。给出了有效杨氏模量、泊松比和热膨胀系数的解析表达式。我们表明，通过调整微观结构几何形状和组成材料，该结构的有效热弹性特性可以广泛地进行调节。特别是，面内有效泊松比和热膨胀系数可在从负到正的很宽范围内进行调整。