Size Effect on the Fracture Strength and Toughness of Nano-cracked CoSb_(3):A Molecular Dynamics Study  

作　　者：Xuqiu Yang Liju Cai Pengcheng Zhai 

机构地区：[1]Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics,Wuhan University of Technology,Wuhan 430070,People’s Republic of China

出　　处：《Acta Mechanica Solida Sinica》2023年第5期685-691,共7页固体力学学报（英文版）

基　　金：funding was provided by the National Natural Science Foundation of China(No.51972253).

摘　　要：Molecular dynamics simulations are implemented to study the mechanical fracture of CoSb_(3) with penetrated nanocracks under the mode-Ⅰ stress.The crack surface and crack front direction are(100)and[001],respectively.It is found that,at a fixed initial crack length,the fracture strength varies with the sample size,but the calculated value of fracture toughness KIC,by employing the classical formula of linear elastic fracture mechanics,maintains constant.When the crack is short in length relative to the sample,the variation of the fracture strength with the initial crack length is well fitted mathematically,and the extrapolation shows rationality even up to the macroscale.More general analyses reveal that,the fracture toughness increases monotonically with increasing the initial crack length until reaching the limit,and the increment is particularly noticeable below 36 nm.Furthermore,different atomic configurations at the crack tip are considered,which show an evident influence on the strength of nano-cracked CoSb_(3).

关 键 词：Fracture strength Fracture toughness Molecular dynamics Size effect Skutterudite CoSb_(3) 

分 类 号：O313[理学—一般力学与力学基础]