文献类型：期刊文献

英文题名：Representative Rupture Stress-Based Parameter for Characterizing the Intensity of Creep Fracture Constraint Effect on Creep Crack Growth Rate

作者：Zhang, Kun[1]; Tan, Jian-Ping[1]; Wen, Jian-Feng[1]; Wang, Guo-Zhen[1]; Tu, Shantung[1]

机构：[1] Key Lab of Pressure Systems and Safety, MOE, School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai, 200237, China

年份：2023

外文期刊名：SSRN

收录：EI(收录号：20230326110)

语种：英文

外文关键词：Crack propagation - Creep - Growth rate

摘要：The introduction of creep fracture constraint parameter offers the possibility of accurately obtaining the CCG rate for specimens/structures subject to various constraint levels by establishing the constraint-dependent CCG rate equation. However, experimental evidence indicates that the existing constraint-dependent CCG rate equation is generally material-dependent and stress regime-dependent. It is noted that the dependency of the existing equation on material and stress regime may be attributed to the intrinsic difference in creep failure mechanisms for materials under creep conditions, which has not been fully considered by previous constraint parameters. To cope with the problem, a parameter, Kz, for characterizing the intensity of constraint effect is proposed in this work using a representative rupture stress concept, which could better reflect the operative creep failure mechanism sustained by the material under consideration. To justify the parameter, finite element analysis is carried out on five different materials based on experimental data available in the literature. Results show that, compared to the existing constraint parameters including R* and Ac, the Kz is capable of characterizing the crack-tip constraint level under the influence of creep failure mechanism. Furthermore, a generalized constraint-dependent CCG rate equation based on the Kz is established, which overcomes the material and stress regime dependencies of the existing equation. Finally, further comparison between the parameter, Kz, and the existing parameter is made to clarify the advantages of the new parameter. ? 2023, The Authors. All rights reserved.