Abstract In recent years, 3D structures with negative Poisson's ratio (auxetic) have attracted great interest. Many polymer and metal 3D auxetic structures have been manufactured using additive manufacturing technology, however composite 3D auxetic structures are rarely reported. Auxetic structures are normally of low stiffness which causes limitations on the structural applications of them. The specific stiffness and strength of auxetic structures can be significantly improved by making them from high-performance fibre reinforced polymer (FRP) composites. Consequently, research of composite 3D auxetic structures made from FRP should be conducted. This paper presents the composite 3D double-arrow-head (DAH) auxetic structure made from carbon fibre reinforced polymer (CFRP) using an assembly method. Experimental, finite element and theoretical methods are adopted to study the mechanical properties of the composite 3D DAH auxetic structures. Results show that the Poisson's ratios and effective compression moduli of the composite 3D DAH auxetic structures vary depending on the compression strain amplitude, and the structures become more auxetic and stiffer with the increase of the compression strain. The specific stiffness of the composite 3D DAH structure is much higher than that of the metal structure. In addition, the dependences of the structure's Poisson's ratio and effective compression modulus on the geometry parameters have also been given. Making auxetic structures from high-performance FRP composites can significantly improve their mechanical properties which will enable them to have a much wider variety of applications.

中文翻译：

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CFRP复合三维双箭头拉胀结构的制备及力学性能

摘要 近年来，负泊松比（拉胀）的 3D 结构引起了人们极大的兴趣。许多聚合物和金属 3D 拉胀结构已使用增材制造技术制造，但很少报道复合 3D 拉胀结构。拉胀结构通常刚度较低，这会限制它们的结构应用。用高性能纤维增强聚合物 (FRP) 复合材料制成拉胀结构的比刚度和强度可以显着提高。因此，应开展由 FRP 制成的复合 3D 拉胀结构的研究。本文介绍了使用组装方法由碳纤维增强聚合物 (CFRP) 制成的复合 3D 双箭头 (DAH) 拉胀结构。实验性的，采用有限元和理论方法研究复合3D DAH拉胀结构的力学性能。结果表明，复合3D DAH拉胀结构的泊松比和有效压缩模量随压缩应变幅值而变化，并且随着压缩应变的增加，结构变得更加拉胀和刚性。复合3D DAH结构的比刚度远高于金属结构。此外，还给出了结构泊松比和有效压缩模量对几何参数的依赖性。用高性能 FRP 复合材料制造拉胀结构可以显着提高其机械性能，这将使它们具有更广泛的应用。