摘要
基于局部表面纳米化技术,本文提出一种适用于重型装备空投的新型缓冲吸能结构设计。与传统吸能结构设计方式不同,本文利用纳米化技术对金属薄壁结构进行局部改性,从而诱导其产生吸能效果最佳的变形模式,该设计方法具有无须改变结构形状、无附加质量等显著优点。首先,介绍了泡沫铝填充式薄壁金属方管的设计流程,并制作了相关试件。其次,基于有限元仿真和试验测试对局部表面纳米化布局进行了优化设计。研究发现,在结构几何尺寸一定的情况下,环向反对称布局方案为最佳设计,此时吸能结构呈现出稳定的渐进层叠的变形模式,形成的褶皱较其他方案更多。最后,进一步研究了表面纳米化对提升该类吸能结构吸能性能的作用机理,并分析了所设计的缓冲平台的吸能效果。结果表明,局部表面纳米化布局不仅提高了薄壁结构自身的吸能性能,同时增强了薄壁结构与泡沫铝之间的相互作用,从而大幅提高整体结构的吸能性能,并且该设计在多柱排列使用时,吸能效果得到进一步加强。
Based on a local surface nanocrystallization technology,a new heavy equipment airdrop buffer system is proposed.Unlike the conventional design method of energy absorption structures,a surface nanocrystallization technology is employed to achieve the locally modification of thin-walled metal structures,therefore the deformation exhibiting the best energy absorbing performance occurrs.This design method has significant advantages such as unchanged structure shape,no additional mass.In this paper,firstly,the design process of aluminum foam-filled thin walled metal square tube is presented and some specimens are fabricated.Secondly,the local surface nanocrystallization layout is optimized based on finite element simulation and experimental test.It is found that,for a certain geometrical size,the circumflex antisymmetric layout scheme is the best design and the energy-absorbing structure presents a stable progressive cascade deformation pattern with more folds than other schemes.Finally,the mechanism of surface nanocrystallization on improvement of the energy absorption performance of such structures is further studied and the energy absorption performance of the proposed buffer system is investigated.The results show that the local surface nano-layout improves the energy absorption performance of the thin-walled structure as well as the interaction between the thin-walled structure and the aluminum foam,therefore the energy absorption performance of the whole structure is greatly improved.Furthermore,the energy absorption performance would be further enhanced by a combination of thin-walled structures.
作者
周若璞
王伟
徐明朗
仝真真
张俊杰
周震寰
Zhou Ruopu;Wang Wei;Xu Minglang;Tong Zhenzhen;Zhang Junjie;Zhou Zhenhuan(State Key Laboratory of Structure Analysis of Industrial Equipment,Dalian University of Technology,Dalian 116024,China;Dalian Jiaotong University,Dalian 116028,China)
出处
《航空科学技术》
2022年第5期82-88,共7页
Aeronautical Science & Technology
基金
国家自然科学基金(12002071)
航空科学基金(2018ZC63003)。
关键词
局部表面纳米化
泡沫铝
薄壁方管
准静态压缩
吸能
有限单元法
local surface nanocrystallization
aluminum foam
thin-walled square
quasi-static compression
energy absorption
finite element method
