分层密度梯度蜂窝材料面内动态压缩及吸能特性  

Dynamic crushing behavior and energy absorption of hexagonal honeycomb material with layered density gradient

作　　者：李坚 孟卫华 张大海 艾兴 LI Jian;MENG Weihua;ZHANG Dahai;AI Xing(AECC Hunan Aviation Power Plant Research Institute,412000,Zhuzhou,China;School of Mechanical Engeering,Southeast University,211189,Nanjing,China)

机构地区：[1]中国航发湖南动力机械研究所,株洲412000 [2]东南大学机械工程学院,南京211189

出　　处：《应用力学学报》2021年第6期2369-2375,共7页Chinese Journal of Applied Mechanics

基　　金：中国航空研究院的航空科学基金资助项目(KYHJ150182)。

摘　　要：基于功能梯度材料概念,通过逐层改变蜂窝胞元壁厚,建立具有固定质量的分层密度梯度六边形蜂窝材料模型。在此基础上,对分层密度梯度六边形蜂窝材料面内冲击性能进行分析,重点讨论了不同冲击速度下密度梯度方向、大小对蜂窝材料压缩变形模式及吸能特性的影响。研究表明:中低速时,密度梯度的变化使得蜂窝材料变形模式及名义应力-应变曲线产生了明显变化,高速时,密度梯度影响较小;吸能方面,不同冲击速度下正密度梯度蜂窝均表现为后段程吸能,而负密度梯度蜂窝材料在中低速和高速冲击时表现是不同的,分别为后段程吸能和前段程吸能;梯度指数越大,蜂窝材料前后段程吸能效率差异越大。通过密度梯度的设计,实现满足不同工程要求的密度梯度蜂窝材料的设计。The concept of functionally gradient materials is introduced into the design of honeycomb materials. A layered density-graded hexagonal honeycomb model with fixed mass is developed via changing cell wall thickness layer by layer. In-plane impact properties of the density-graded honeycomb material are analyzed;the effects of gradient orientation and gradient magnitude on the deformation and energy absorption capacities of hexagonal honeycombs are discussed. The results show that changing the density gradient produces a great effect on deformation modes and nominal stress-strain curves of the honeycomb in the low speed cases and a small effect in the high speed cases. The energy absorption efficiency of honeycombs with positive gradient increases with compressing, which is a back-end energy absorption mode. Negative graded honeycombs are basically the same as the positive graded honeycombs in the low speed cases, which becomes the front-end energy absorption mode under high speed impacts. Besides, the higher the density gradient is, the bigger the difference of energy absorption efficiency between the front-end and back-end becomes. These results can provide some useful suggestions on density graded honeycomb design to meet different engineering requirements.

关 键 词：蜂窝 密度梯度 面内冲击 变形模式 能量吸收 

分 类 号：O341[理学—固体力学]