文献类型：期刊文献

英文题名：Effects of creep properties of materials on creep crack-tip constraint parameter R*

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

机构：[1]E China Univ Sci & Technol, Minist Educ, Key Lab Pressure Syst & Safety, Shanghai 200237, Peoples R China

年份：2016

卷号：33

期号：2

起止页码：208

外文期刊名：MATERIALS AT HIGH TEMPERATURES

收录：;EI(收录号：20162102406374);WOS:【SCI-EXPANDED(收录号:WOS:000375870000011)】；

基金：This work is supported by the Projects of the National Natural Science Foundation of China [grant numbers: 51375165, 51575184, 51325504].

语种：英文

外文关键词：Creep; Constraint parameter R*; Creep exponent; Finite element analyses; Steel

摘要：Extensive finite element analyses have been conducted to investigate the effect of creep properties of materials on the creep crack-tip constraint parameter R*. The results show that the parameter R* increases with increasing power law creep stress exponent n of materials, and it is sensitive to lower n values and lower in-plane and out-of-plane constraints. In the engineering estimations of the creep constraint parameter R*, only the creep exponent effect needs to be considered for cracked components with lower exponent n and lower constraint, and the Norton's coefficient A of power law creep materials can be ignored due to its insensitivity to the R*. The R*-n relation formulae have been established for single-edge-notched tension specimen (it has similar constraint level to pressurised pipes) with different in-plane and out-of-plane constraints, and they may be used to estimate the creep crack-tip constraint levels for cracked pipes with lower exponent n and lower constraint.