文献类型：期刊文献

英文题名：Unified characterisation of in-plane and out-of-plane constraint based on crack-tip equivalent plastic strain

作者：Yang, J.[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：2013

卷号：36

期号：6

起止页码：504

外文期刊名：FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES

收录：;EI(收录号：20132216367035);WOS:【SCI-EXPANDED(收录号:WOS:000319145000004)】；

基金：This work was financially supported by the Project of the National Natural Science Foundation (51075149, 50835003), the National High Technology Research and Development Program (2012AA040103) and the Fundamental Research Funds for the Central Universities of China.

语种：英文

外文关键词：crack-tip equivalent plastic strain; fracture toughness; GTN damage model; in-plane constraint; out-of-plane constraint

摘要：Constraint can be divided into two conditions of in-plane and out-of-plane, and each of them has its own parameter to characterize. However, in most cases, there exists a compound change of both in-plane and out-of-plane constraint in structures, a unified measure that can reflect both of them is needed. In this paper, the finite element method (FEM) was used to calculate the equivalent plastic strain (p) distribution ahead of crack tips for specimens with different in-plane and out-of-plane constraints, and the FEM simulations based on GursonTvergaardNeedleman (GTN) damage model and a small number of tests were used to obtain fracture toughness for the specimens with different constraints. Unified measure and characterisation parameter of in-plane and out-of-plane constraints based on crack-tip equivalent plastic strain has been investigated. The results show that the area APEEQ surrounded by the p isoline ahead of crack tips can characterize both in-plane and out-of-plane constraints. Based on the area APEEQ, a unified constraint characterisation parameter Ap was defined. It was found that there exists a sole linear relation between the normalised fracture toughness JIC/Jref and regardless of the in-plane constraint, out-of-plane constraint and the selection of the p isolines. The unified JIC/Jrefreference line can be used to determine constraint-dependent fracture toughness of materials. The FEM simulations with the GTN damage model (local approach) can be used in obtaining the unified JIC/Jrefreference line for materials with ductile fracture.