泡沫填充四韧带反手性结构和内凹结构的面内压缩性能

In-plane compression properties of foam-filled anti-tetrachiral structure and re-entrant structure

  • 摘要: 负泊松比蜂窝结构具有优良的力学性能,包括抗压痕性、抗冲击性、吸能性。为了更好地研究负泊松比结构的力学性能,分别选取了内凹结构和四韧带反手性结构两种负泊松比结构进行对比分析。为了提高蜂窝结构的力学性能,在结构中填充聚氨酯泡沫材料。并对填充后的内凹结构和四韧带反手性结构的变形模式和力学性能进行了试验研究。此外通过对填充四韧带反手性结构进行参数研究,分析了壁厚t和节点半径r对结构吸能性和泊松比的影响。研究结果表明:四韧带反手性结构比内凹结构的吸能性好、承载能力强。对两种结构分别进行填充后,结构具有更高的刚度和吸能性,但是“拉胀”效应减弱。随着壁厚t和节点半径r的增加,填充四韧带反手性结构的刚度和能量吸收能力增强,泊松比值增大,“拉胀”效应减弱。但是壁厚过大会使结构脆性破坏增强,其比吸能性降低。另外随着壁厚t增大、节点半径减小,填充四韧带反手性结构的压实应变减小。

     

    Abstract: Negative Poisson's ratio honeycomb structure has excellent mechanical properties including indentation resistance, impact resistance and energy absorption. In order to better study the mechanical properties of negative Poisson's ratio structure, this paper selects two kinds of negative Poisson's ratio structure: Anti-tetrachiral structure and re-entrant structure for comparative analysis. In order to improve the mechanical properties of honeycomb structure, polyurethane foam was filled in the structure. The deformation modes and mechanical properties of the foam-filled anti-tetrachiral structure and re-entrant structure were experimentally studied. In addition, through the parametric study of the foam-filled anti-tetrachiral structure, the effects of wall thickness t and node radius r on the energy absorption and Poisson's ratio of the structure were analyzed. The results show that the energy absorption and bearing capacity of anti-tetrachiral structure is better than that of the re-entrant structure. After filling the two kinds of structures respectively, the structure has higher stiffness and energy absorption, but the ‘auxetics’ effect is weakened. With the increase of wall thickness t and node radius r, the stiffness and energy absorption capacity of the foam-filled anti-tetrachiral structure increase, the Poisson's ratio increases, and the "auxetics" effect decreases. However, the brittle failure of the structure is enhanced and its specific energy absorption is weakened when the wall thickness is too thick. In addition, the compaction strain of the four-ligament backhand structure decreases with the increase of the wall thickness t and the decrease of the node radius r.

     

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