摘要
通过运用电镜扫描(SEM)及断层扫描技术(XCT)对单个金属空心球体球壁表面及内部孔隙特征及分布进行观测,得出球壁中孔隙率的范围,并结合实验和数值模拟,分析在准静态压缩条件下,金属空心球的变形过程,分析了孔隙率及其分布对金属空心球变形破坏模式的影响.结果表明:金属空心球的准静态单轴压缩其变形主要包括弹性变形、屈曲和屈服变形、球壁坍塌变形和致密化4个阶段;当单个金属空心球球壁处存在薄弱区域时,该区域在受力后会首先发生屈曲破坏,进而向内凹陷,若破坏区域相互毗邻或相近,则会形成一条或多条失稳线,球体会沿着失稳线破坏,且失稳线周围会形成铰结构,提高球体的承载能力.研究结果为金属空心球泡沫材料的设计和制造提供理论参考.
A scanning electron microscope(SEM) and X-ray tomography(XCT) were conducted to probe the morphology of the thin wall and get the range of the microporosity,as well as the deformation process and failure of single metallic hollow sphere(MHS)with different distributions of microporosities on the thin wall were analyzed by finite element modelling(FEM) simulation and experimental tests.The results show that the deformation process is summarized into four stages,elasticity,buckling and yielding,collapse and densification,separately.And for the effect of the microporosity,when there exist weak regions on the local partitions of the single MHS thin wall, the weak regions will buckle first and generate buckling lines on the single MHS if they are adjacent.The buckling failures will occur along these buckling lines on the MHS under the quasi-static compression,among the buckling lines will generate hinges which make contributions on load capacity during the densification process.The results provide some theoretical guidance on the design and manufacturing of metallic hollow sphere foams.
作者
宋金良
刘婉姝
孙全胜
杨金水
SONG Jinliang;LIU Wanshu;SUN Quansheng;YANG Jinshui(School of Civil E nginecring,Northeast Forestry University,Harbin 150040,China;State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan430071,China;College of Aerospace and Civil Engineering,Harbin Engineering University,Harbin 150001,China)
出处
《华中科技大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2020年第8期26-32,共7页
Journal of Huazhong University of Science and Technology(Natural Science Edition)
基金
国家自然科学基金青年基金资助项目(11802070)。
关键词
金属空心球
孔隙率
压缩变形
破坏模式
准静态压缩实验
数值模拟
metallic hollow sphere
micro-porosity
compression deformation
failure mode
quasi-static compression test
numerical simulation
