摘要
由高强度高刚度薄片随机组装而成的片状网络材料具有独特的性能和广泛的应用.然而,网络具有显著的随机和离散特征,这些特征对材料的强度和韧性的影响机理还不明确.为此,本文系统研究了随机薄片网络材料在单轴拉伸载荷下的损伤失效演化过程,发现了该类材料强度的缺口不敏感性,并揭示了其机理.研究表明,由于网络材料自身的随机和离散特征,层间连接强弱不均且分布随机,因此在单轴拉伸过程中,损伤从弱连接处萌生,并在空间多点离散分布,最终逐渐汇聚成为主裂纹,使得网络呈现韧性断裂特征.正是由于初始损伤为多点分布形式且缺口尖端应力集中有限,导致了随机薄片网络的强度对缺口的不敏感,且与薄片和层间连接的韧性无关.
Plate-like network materials randomly assembled from high-strength sheets have unique properties and numerous applications.However,the network has significant random and discrete characteristics,and the mechanism of the influence of these characteristics on the strength and toughness of the material remains unclear.This study aims to elucidate the damage failure evolution process of random sheet network materials under uniaxial tensile load is systematically studied.The notch insensitivity of the strength of such materials is determined,and its mechanism is revealed.This study shows that the interlayer connections have uneven strength and are randomly distributed because of the random and discrete characteristics of the network material.Therefore,in the uniaxial tensile process,damage starts from the weak connection,distributes discretely at multiple points in space,and eventually converges to the main crack,thus making the network exhibit ductile fracture characteristics.Owing to the multipoint distribution of initial damage and the limited stress concentration at the notch tip,the strength of the random sheet network is insensitive to the notch and independent of the toughness of the sheet and interlayer connection.
作者
张峰
潘飞
陈玉丽
ZHANG Feng;PAN Fe;CHEN YuLi(Tianmushan Laboratory,Hangzhou 310023,China;School of Aeronautic Science and Engineering,Beihang University,Bejing 100191,China;Xiamen Shuangrui Wind Power Technology Co.Ltd.,Xiamen 361000,China)
出处
《中国科学：物理学、力学、天文学》
CSCD
北大核心
2024年第5期253-268,共16页
Scientia Sinica Physica,Mechanica & Astronomica
基金
国家重点研发计划(编号:2020YFB1313003)
国家自然科学基金(编号:12002016,12172026,12225201)资助项目。
关键词
随机薄片网络
强度
韧性
缺口敏感性
random sheet network
strength
toughness
notch sensitivity
