Molecular dynamics simulation of fatigue crack propagation in bcc iron under cyclic loading
The mechanisms of fatigue crack propagation under cyclic loading in iron single crystal was investigated using a molecular dynamics simulation.The deformation in fatigue crack growth in several typical models was performed using pre-existing centre crack specimens.The cyclic loading was strain controlled under loading and unloading.The modes of 100 (001) crack,001- (1-10) crack and 11-2 (110) crack were studied and the results showed that the rate of crack growth was different for the three models.Not only the main deformation: persistent slip bands,but also vacancies and voids nucleation were observed during the evolution process of crack growth under cyclic loading.The slip plane of 100 (001) crack were (112) and 001- (1-10) crack slip along (110) plane.While no significant slip band was observed in 112- (110) crack,crack propagation was brittleness.Furthermore,the analysis of the influences of grain boundary was carried out on Σ 3<112> 111 and Σ 5<310> 001 models.The result showed that Σ 3 resisted failure and no slip band was observed,and stress concentration caused brittle fracture by fatigue crack propagation.While Σ 5 play an important role on fatigue crack propagation,the simulation results indicated that grain boundary resisted obviously crack growth and leaded to the rate of crack growth decreasing.The plastic deformation zone including most face center cubic (fcc) slip band and a little hexagonal close-packed (hcp) slip band.
Molecular dynamics Fatigue crack growth orientation
LeiMa Shifang Xiao Huiqiu Deng Wangyu Hu
Department of Materials & Engineering,Hunan University,Changsha 410082 China Department of Applied Physics,Hunan University,Changsha 410082,P.R.China Department of Materials & Engineering,Hunan University,Changsha 410082 China;Department of Applied P
国际会议
北京
英文
1-12
2013-06-16（万方平台首次上网日期，不代表论文的发表时间）