文献类型：会议论文

英文题名：In situ near-tip normal strain evolution of a growing fatigue crack

作者：Zhu, M. -L.[1,2,3];Lu, Y. -W.[1];Lupton, C.[1];Tong, J.[1]

机构：[1]Univ Portsmouth, Sch Engn, Mech Behav Mat Lab, Portsmouth, Hants, England;[2]East China Univ Sci & Technol, Minist Educ, Key Lab Pressure Syst & Safety, Shanghai, Peoples R China;[3]East China Univ Sci & Technol, Sch Mech & Power Engn, Shanghai, Peoples R China

会议论文集：3rd International Conference on Characterisation of Crack Tip Fields

会议日期：APR 20-22, 2015

会议地点：Urbino, ITALY

语种：英文

外文关键词：crack tip; DIC; error analysis; fatigue crack growth; strain ratchetting

摘要：Normal strains near a growing fatigue crack have been studied in situ using the Digital Image Correlation technique in a compact tension specimen of stainless steel 316L under tension-tension cyclic loading. An error analysis of the measured displacements and strains has been carried out, and the results show that the precisions of displacements and strains in the direction perpendicular to the crack plane and ahead of the crack are better than those parallel to the crack plane and in the wake of the crack. The errors in the measured displacements are in the range of 0.06 to 0.1 mu m and between 0.2% and 0.4% for the measured strains, the latter are well below the critical strain at the onset of crack growth about 8%. Strain ratchetting was found ahead of the growing fatigue crack tip, albeit very close to the crack tip.