Wang Jiajun, Chen Zhaochang, Jiao Pengcheng, Alavi Amir H
Ocean College, Zhejiang University, Zhoushan, Zhejiang, China.
Engineering Research Center of Oceanic Sensing Technology and Equipment, Ministry of Education, Hangzhou, Zhejiang, China.
Research (Wash D C). 2024 Aug 30;7:0463. doi: 10.34133/research.0463. eCollection 2024.
Auxetic materials have been extensively studied for their design, fabrication and mechanical properties. These material systems exhibit unique mechanical characteristics such as high impact resistance, shear strength, and energy absorption capacity. Most existing auxetic materials are two-dimensional (2D) and demonstrate half-auxetic behavior, characterized by a negative Poisson's ratio when subjected to either tensile or compressive forces. Here, we present novel three-dimensional (3D) auxetic mechanical metamaterials, termed coupling chiral cuboids, capable of achieving negative Poisson's ratio under both tension and compression. We perform experiments, theoretical analysis, and numerical simulations to validate the wholly auxetic response of the proposed coupling chiral cuboids. Parametric studies are carried out to investigate the effects of structural parameters on the elastic modulus and Poisson's ratio of the coupling chiral cuboids. The results imply that the Poisson's ratio sign-switching from negative to positive can be implemented by manipulating the thickness of Z-shaped ligaments. Finally, the potential application of the coupling chiral cuboids as inner cores for impact-resistant sandwich panels is envisioned and validated. Test results demonstrate a remarkable 49.3% enhancement in energy absorption compared to conventional solid materials.
对拉胀材料的设计、制造及其力学性能进行了广泛研究。这些材料体系表现出独特的力学特性，如高抗冲击性、抗剪强度和能量吸收能力。大多数现有的拉胀材料是二维的，并表现出半拉胀行为，其特征是在受到拉力或压力时泊松比为负。在此，我们提出了一种新型的三维拉胀力学超材料，称为耦合手性长方体，它能够在拉伸和压缩状态下均实现负泊松比。我们进行了实验、理论分析和数值模拟，以验证所提出的耦合手性长方体的全拉胀响应。开展了参数研究，以研究结构参数对耦合手性长方体弹性模量和泊松比的影响。结果表明，通过控制Z形韧带的厚度，可以实现泊松比从负到正的切换。最后，设想并验证了耦合手性长方体作为抗冲击夹芯板内芯的潜在应用。测试结果表明，与传统固体材料相比，能量吸收显著提高了49.3%。
