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基于旋转内凹六边形的负泊松比结构力学性能研究
MECHANICAL PERFORMANCE OF NEGATIVE POISSON’S RATIO STRUCTURES BASED ON ROTATING CONCAVE HEXAGON
【摘要】 为提升负泊松比结构的力学性能,基于旋转刚体结构与内凹多边形结构的变形机理,将常规内凹六边形旋转一定角度,得到旋转内凹六边形负泊松比结构。首先,推导了该结构的相对密度、等效弹性模量、等效泊松比等等效性能的理论公式,并通过仿真计算加以验证。利用有限元软件LS-Dyna进行模拟计算,对比分析了旋转内凹六边形与常规内凹六边形在不同冲击速度下的动力学特性,讨论了旋转内凹六边形负泊松比结构的吸能特性与胞壁厚度、旋转角度、夹角等结构参数之间的关系。结果表明,该结构的名义应力-应变曲线具有多段平台应力特征,与同质量的常规结构相比,该结构平台应力段更长,能量吸收性能更优异。该研究为提升多胞结构的抗冲击动力学性能提供了思路。
【Abstract】 In order to improve the mechanical performance of the negative Poisson’s ratio structure, based on the deformation mechanism of rotating rigid body structure and concave polygon structure, conventional concave hexagon was rotated by a certain angle to obtain the negative Poisson’s ratio(NPR) structure of rotating concave hexagon. Firstly, the theoretical formulas of structural equivalent performance, such as relative density, equivalent elastic modulus, and equivalent Poisson’s ratio, were derived, and verified by simulation calculation. The finite element software LS-Dyna was used to simulate and analyze the dynamic characteristics of rotating concave hexagon and conventional concave hexagon under different impact velocities, and the relationship between energy absorption characteristics of rotating concave hexagon NPR structure and structural parameters such as cell wall thickness, rotation angle and included angle was discussed. The results show that the nominal stress-strain curves of the structure have multi-stage platform stress characteristics. Compared with conventional structure with the same mass, the new structure has longer platform stress section and better energy absorption performance. This study provides an idea for improving impact resistance of multicellular structures.
【Key words】 Negative Poisson’s ratio; Mass ratio energy absorption; Energy absorption characteristics; Finite element simulation; Dynamic crushing;
- 【文献出处】 机械强度 ,Journal of Mechanical Strength , 编辑部邮箱 ,2023年01期
- 【分类号】O342
- 【下载频次】94