新型负泊松比材料等效性能与吸能性能研究

STUDY ON THE EQUIVALENT PROPERTIES AND ENERGY ABSORPTION PROPERTIES OF A NOVEL MATERIAL WITH NEGATIVE POISSON′S RATIO

近年来,负泊松比(Negative Poisson′s Ratio,NPR)材料以其优异的力学性能与在传统工业领域巨大的应用潜力引起了学术界的广泛关注。设计并研究了一种新型负泊松比材料(基于YSH结构胞元)在动态压缩工况下的力学性能。通过有限元仿真的方法,对比了不同结构参数(斜壁倾角、宽度比、纵横比)对胞元等效力学性能参数的响应差异,探究了这些结构参数对吸能性能的影响程度,并进一步扩展到对四种常见的功能梯度阵列排布下的结构的研究。采用吸能量Ea、吸能效率Eε和平台应力σp三个指标评判了结构的能量吸收效果。研究发现:斜壁倾角θ越大,结构整体的能量吸收表现越佳;宽度比α对于结构整体的等效力学性能与能量吸收均影响较小;纵横比β越小,结构的负泊松比效应越明显,但相反地,其数值越大却能带来更高的能量吸收效率。所得结果可为负泊松比材料的功能导向设计提供参考。

In recent years,negative Poisson′s ratio(NPR)materials have attracted extensive attention from the academic community due to their excellent mechanical properties and huge application potential in traditional industrial fields.The mechanical properties of a new type of material with negative Poisson′s ratio(based on YSH structural cell)under dynamic compression are designed and studied.Through the finite element simulation method,the response difference of different structural parameters(inclined wall angle,width ratio,aspect ratio)to the equivalent elastic mechanical performance parameters of the cell is compared,and the influence of these structural parameters on the energy absorption performance is explored,and the research is further extended to the structure under four common functional gradient arrays.The energy absorption effect of the structure is evaluated by three indexes:energy absorption,energy absorption efficiency and platform stress.The study shows that,inclined wall inclinationθthe larger,the better the energy absorption performance of the whole structure;width ratioαit has little influence on the equivalent mechanical properties and energy absorption of the whole structure;aspect ratioβthe smaller the value,the more obvious the negative Poisson′s ratio effect of the structure,but on the contrary,the larger the value,the higher the energy absorption efficiency.The results can provide a reference for the function-oriented design of materials with negative Poisson′s ratio.