Affiliation of Author(s):航空学院
Journal:INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
Key Words:Creeping crack border fields Two-parameter description C(r)-T-z Three-parameter description C(t)-T-z-T-Q* Through-thickness cracks Corner cracks Surface cracks
Abstract:Creeping fracture in engineering always occurs in high temperature structures with complicated geometries and loading configurations, and how to characterize the three-dimensional crack border stress fields is essentially important to design of the structures. By comprehensive finite element analyses of specimens with through-the-thickness cracks and specimens with corner, surface and embedded elliptic cracks, we demonstrated that a three-parameter characterization based on C(t) integral, the out-of-plane stress constraint factor T-z and in-plane constraint coefficient Q* can be efficiently applied in all cases. It is shown that a two-parameter C(t)-T-z solution can provide efficient prediction for the stress field ahead of the crack under small scale creep condition. Under large scale creep conditions, it is found that Tz has nearly a unified distribution ahead of cracks, and the three-parameter C(t)-T-z solution can characterize the crack front stress fields efficiently. This universal characterization of the creeping crack front stress field should serve as a solid fundamental for three-dimensional damage tolerant design of high temperature structures. (C) 2018 Elsevier Ltd. All rights reserved.
ISSN No.:0020-7683
Translation or Not:no
Date of Publication:2018-11-01
Co-author:Chen, Zhiyuan,SHE ChongMin
Correspondence Author:Guo Wanlin
Date of Publication:2018-11-01