Effect of cooperative grain boundary sliding and migration on dislocation emitting from a semi-elliptical blunt crack tip in nanocrystalline solids

被引：0
作者：
Min Yu
Qihong Fang
Hui Feng
Youwen Liu
机构：
[1] Hunan University,State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body
[2] Central South University of Forestry and Technology,College of Civil Engineering and Mechanics
来源：
Acta Mechanica | 2014年 / 225卷
关键词：
Fracture Toughness; Stress Intensity Factor; Grain Bind; Edge Dislocation; Nanocrystalline Material;
D O I：
暂无
中图分类号：
学科分类号：
摘要：
A theoretical model is established to investigate the interaction between the cooperative grain boundary (GB) sliding and migration and a semi-elliptical blunt crack in deformed nanocrystalline materials. By using the complex variable method, the effect of two disclination dipoles produced by the cooperative GB sliding and migration process on the emission of lattice dislocations from a semi-elliptical blunt crack tip is explored. Closed-form solutions for the stress field and the force acting on the dislocation are obtained in complex form, and the critical stress intensity factors for the first dislocation emission from a blunt crack under mode I and mode II loadings are calculated. Then, the influence of disclination strength, curvature radius of blunt crack tip, crack length, locations and geometry of disclination dipoles, and grain size on the critical stress intensity factors is presented detailedly. It is shown that the cooperative GB sliding and migration and the grain size have significant influence on the dislocation emission from a blunt crack tip.
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页码：2005 / 2019
页数：14
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