构型对正多边形蜂窝异面缓冲性能的影响

Influence of Configuration on Out-of-plane Cushioning Performance of Regular Polygonal Honeycombs

目的利用有限元法研究应变率不敏感的双线性各向同性应变硬化正多边形(等边三角形、正方形、正六边形和正八边形)蜂窝的异面缓冲性能。方法建立基于正多边形蜂窝特征单元的异面冲击分析有限元模型,提出最佳应变这一缓冲性能评价新指标,基于此重新定义各能量吸收评价指标,形成新缓冲性能评价方法。结果以此获取不同相对密度的各正多边形蜂窝在不同冲击速度下的变形模式和应力-应变曲线,以及平均平台应力、比能量吸收和冲击力效率等评价指标值,并进行了分析。结论给定相对密度下,正八边形蜂窝具有最大的异面平均平台应力;正多边形蜂窝的比能量吸收与冲击速度成二次关系;定密度的正六和八边形蜂窝的冲击力效率优于等边三角形和正方形蜂窝。

The work aims to study the cushioning performance of regular polygonal(equilateral triangular,square,regular hexagonal and regular octagonal)honeycombs with the elastic linear strain-hardening(bilinear)isotropic base material under out-of-plane impact through the finite element method.Finite element models based on the regular polygonal honeycomb cells were established for their out-of-plane impact analysis.Based on the proposed new evaluation indicator of most appropriate strain,all cushioning performance evaluation indicators were redefined to form a novel cushioning performance evaluation method.Their deformation modes,stress strain curves,and some cushioning performance evaluation indicators such as mean plateau stress,specific energy absorption and impact force efficiency of regular polygonal honeycombs with different relative densities under different impact velocities were obtained and analyzed.The regular octagonal honeycomb has the maximum mean plateau stress for a given relative density.The specific energy absorption of each regular polygonal honeycomb relies on the impact velocity in a quadratic polynomial curve.The regular hexagonal and octagonal honeycombs with same relative densities outperform equilateral triangular and square honeycombs in impact force efficiency.