新型三维负泊松比蜂窝结构设计与力学性能研究

Structural design and mechanical characterisation of a novel three-dimensional negative poisson's ratio honeycomb

负泊松比蜂窝结构具备优良的力学性能、出色的能量吸收能力和轻量化特性,使其在减振降噪、抗爆抗冲击等领域中具有重要应用价值,可广泛应用于舰船高性能结构设计中。本文基于典型二维内凹六边形设计了一种三维度均具备负泊松比效应的新型蜂窝结构。利用其构型的高度对称性对结构受力模型进行简化,基于Timoshenko梁理论构建了该结构在准静态载荷作用下的等效力学模型。通过对比理论解、有限元结果与试验结果三者,验证了所建立的新型负泊松比蜂窝结构力学模型的合理性,为该新型结构力学性能的预测提供了一种便捷且较为准确的方法。此外,进一步分析了三维负泊松比蜂窝中微观胞元各几何参数对结构整体性能的影响。结果表明,通过对胞元几何形状的针对性优化可完成对其力学性能的控制,为后续该型结构的实际应用提供了理论依据。

Negative Poisson's ratio honeycomb structure owns excellent mechanical properties, good energy absorption capacity and lightweight characteristics, making it of significant application value in the fields such as vibration reduction and anti-blast and impact resistance. In this paper, a new type of three-dimensional negative Poisson's ratio honeycomb(3D-NPH) structure was proposed based on a typical two-dimensional re-entrant hexagon. Due to the high symmetry of such structure, the analysis model can be simplified, and the equivalent mechanical model of 3D-NPH under quasi-static load was deduced using the Timoshenko beam theory. By comparing theoretical solutions, Finite-element-analysis(FEA) results and experimental results, the rationality of the 3D-NPH theoretical mechanical model can be verified, which provides a convenient and relatively accurate way in the prediction of the performance for the 3D-NPH structure. Furthermore, the influence of geometries on the mechanical properties for 3D-NPH were also discussed. The results indicate that the mechanical properties can be controlled via the targeted optimization of its geometry, which can provide a theoretical basis for the practical application of this 3D-NPH structure.