Abstract A new class of lightweight and 3D printable architected sandwich structures, named as meta-sandwich structures, has been introduced. These lightweight sandwich structures, which have been made of mechanical metamaterials as the core, show many advantages such as high stiffness-to-weight ratio and high energy absorption capability. In this paper, finite element simulation and experimental testing were implemented to evaluate the structural durability of 3D printed meta-sandwiches under quasi-static flexure and low-velocity impact tests. We specifically investigated the failure mechanism, energy absorption and multi-hit capability of 3D printed polymeric meta-sandwich structures made of cubic, octet and Isomax cellular cores. Three-point bending experiments on 3D printed meta-sandwich beams were conducted to evaluate their flexural stiffness and quasi-static energy absorption, followed by low-velocity impact tests to determine their dynamic energy absorption and multi-hit capabilities. Analytical formulations were also developed to capture the failure mechanism in the architected sandwich structures. It is found that the core topology and geometrical parameters have significant effects on failure mechanism and energy absorption of meta-sandwich structures. For example, Isomax meta-sandwich structures show high quasi-static and dynamic impact energy absorption capabilities.

中文翻译：

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3D 打印的超三明治结构：失效机制、能量吸收和多重打击能力

摘要 引入了一类新的轻量级和 3D 可打印的夹层结构，称为元夹层结构。这些以机械超材料为核心的轻质夹层结构显示出高刚度重量比和高能量吸收能力等诸多优点。在本文中，实施有限元模拟和实验测试，以评估 3D 打印元三明治在准静态弯曲和低速冲击测试下的结构耐久性。我们专门研究了由立方体、八位位组和 Isomax 细胞核制成的 3D 打印聚合物元三明治结构的失效机制、能量吸收和多次打击能力。对 3D 打印的超夹心梁进行了三点弯曲实验以评估它们的弯曲刚度和准静态能量吸收，然后进行低速冲击试验以确定它们的动态能量吸收和多次冲击能力。还开发了分析公式来捕捉建筑夹层结构中的失效机制。发现核心拓扑和几何参数对超夹心结构的破坏机制和能量吸收有显着影响。例如，Isomax 元三明治结构表现出高准静态和动态冲击能量吸收能力。还开发了分析公式来捕捉建筑夹层结构中的失效机制。发现核心拓扑和几何参数对超夹心结构的破坏机制和能量吸收有显着影响。例如，Isomax 元三明治结构表现出高准静态和动态冲击能量吸收能力。还开发了分析公式来捕捉建筑夹层结构中的失效机制。发现核心拓扑和几何参数对超夹心结构的破坏机制和能量吸收有显着影响。例如，Isomax 元三明治结构表现出高准静态和动态冲击能量吸收能力。