Purpose

Auxetics metamaterials show high performance in their specific characteristics, while the absolute stiffness and strength are much weaker due to substantial porosity. This paper aims to propose a novel auxetic honeycomb structure manufactured using selective laser melting and study the enhanced mechanical performance when subjected to in-plane compression loading.

Design/methodology/approach

A novel composite structure was designed and fabricated on the basis of an arrowhead auxetic honeycomb and filled with polyurethane foam. The deformation mechanism and mechanical responses of the structure with different structural parameters were investigated experimentally and numerically. With the verified simulation models, the effects of parameters on compression strength and energy absorption characteristics were further discussed through parametric analysis.

Findings

A good agreement was achieved between the experimental and simulation results, showing an evidently enhanced compression strength and energy absorption capacity. The interaction between the auxetic honeycomb and foam reveals to exploit a reinforcement effect on the compression performance. The parametric analysis indicates that the composite with smaller included angel and higher foam density exhibits higher plateau stress and better specific energy absorption, while increasing strut thickness is undesirable for high energy absorption efficiency.

Originality/value

The results of this study served to demonstrate an enhanced mechanical performance for the foam filled auxetic honeycomb, which is expected to be exploited with applications in aerospace, automobile, civil engineering and protective devices. The findings of this study can provide numerical and experimental references for the design of structural parameters.

中文翻译：

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PU泡沫填充铝箭头拉胀蜂窝面内单轴压缩响应的实验与数值研究

目的

拉胀超材料在其特定特性中表现出高性能，但由于大量孔隙率，绝对刚度和强度要弱得多。本文旨在提出一种采用选择性激光熔化制造的新型拉胀蜂窝结构，并研究在承受面内压缩载荷时增强的机械性能。

设计/方法论/途径

基于箭头拉胀蜂窝结构并填充聚氨酯泡沫，设计并制造了一种新型复合材料结构。通过实验和数值研究了不同结构参数的结构的变形机制和力学响应。在经过验证的仿真模型的基础上，通过参数分析进一步讨论了参数对抗压强度和吸能特性的影响。

发现

实验与模拟结果吻合良好，显示出抗压强度和能量吸收能力明显增强。拉胀蜂窝体和泡沫之间的相互作用揭示了对压缩性能的增强作用。参数分析表明，较小的夹角和较高的泡沫密度的复合材料表现出较高的平台应力和更好的比能量吸收，而增加支柱厚度不利于高能量吸收效率。

原创性/价值

这项研究的结果证明了泡沫填充拉胀蜂窝的机械性能增强，预计将在航空航天、汽车、土木工程和防护装置中得到应用。本研究结果可为结构参数设计提供数值和实验参考。