文献类型：会议论文

英文题名：Near-tip strain evolution and crack closure of growing fatigue crack under a single tensile overload

作者：Chen, Rong[1];Zhu, Ming-Liang[1];Xuan, Fu-Zhen[1];Wu, Sheng-Chuan[2];Fu, Ya-Nan[3]

机构：[1]East China Univ Sci & Technol, Key Lab Pressure Syst & Safety, Minist Educ, Sch Mech & Power Engn, Shanghai 200237, Peoples R China;[2]Southwest Jiaotong Univ, State Key Lab Tract Power, Chengdu 610031, Peoples R China;[3]Chinese Acad Sci, SSRF, Shanghai Adv Res Inst, Shanghai, Peoples R China

会议论文集：6th International Conference on Crack Paths (CP)

会议日期：SEP 19-21, 2018

会议地点：Verona, ITALY

语种：英文

外文关键词：In-situ SEM; 3D synchrotron; Overload effect; Residual stress; Crack closure

摘要：Fatigue crack growth retardation of AZ31 alloy under a single tensile overload was investigated by 3D synchrotron radiation, 2D in-situ SEM and digital image correlation techniques. Results showed a consistent evolution of crack closure level by both 3D and 2D methodologies. The straining and plastic zone ahead of crack-tip, and crack opening displacement behind, which were quantitative indicators of crack-tip shielding, residual stress formation and relaxation, were correlated well with the retardation behavior. Mechanistically, compressive residual stress played a dominant but time-limited role while crack closure was secondary, based on an intrinsic load transfer concept during crack growth.