文献类型：期刊文献

英文题名：Effect of constraint induced by crack depth on creep crack-tip stress field in CT specimens

作者：Wang, G. Z.[1];Liu, X. L.[1];Xuan, F. Z.[1];Tu, S. T.[1]

机构：[1]E China Univ Sci & Technol, MOE Key Lab Safety Sci Pressurized Syst, Sch Mech & Power Engn, Shanghai 200237, Peoples R China

年份：2010

卷号：47

期号：1

起止页码：51

外文期刊名：INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES

收录：;EI(收录号：20094612449248);WOS:【SCI-EXPANDED(收录号:WOS:000272694000005)】；

基金：This work was financially supported by the Key Project of the National Natural Science Foundation of China (No.50835003), the National High Technology Research and Development Program of China(2009AA04Z409), and the Doctoral Fund of Ministry of Education of China(200802510003).

语种：英文

外文关键词：Constraint; Creep; Stress field; Crack; CT specimen

摘要：In this paper, the effect of constraint induced by the crack depth on creep crack-tip stress field in compact tension (CT) specimens is examined by finite element analysis, and the effect of creep deformation and damage on the Hutchinson-Rice-Rosengren (HRR) singularity stress field are discussed. The results show the constraint induced by crack depth causes the difference in crack-tip opening stress distributions between the specimens with different crack depth at the same C*. The maximum opening stress appears at a distance from crack tips, and the stress singularity near the crack tips does not exist due to the crack-tip blunting caused by the large creep deformation in the vicinity of the crack tips. The actual stress calculated by the finite element method (FEM) in front of crack tip is significantly lower than that predicted by the HRR field. Based on the reference stress field in the deep crack CT specimen with high constraint, a new constraint parameter R is defined and the constraint effect in the shallow crack specimen is examined at different distances ahead of the crack tip from transient to steady-state creep conditions. During the early stages of creep constraint increases with time, and then approaches a steady state value as time increases. With increasing the distance from crack tips and applied load, the negative R increases and the constraint decreases. (C) 2009 Elsevier Ltd. All rights reserved.