Crack growth rate of inclined and deflected surface-cracks in round-bar specimens of copper processed by equal channel angular pressing under cyclic loading

被引：8

作者：

Goto, M. ^{[1
]}

Yamamoto, T. ^{[1
]}

Han, S. Z. ^{[2
]}

Kim, S. ^{[3
]}

Ahn, J-H. ^{[2
]}

Kitamura, J. ^{[1
]}

Iwarnura, T. ^{[1
]}

Lee, J. ^{[4
]}

机构：

[1] Oita Univ, Dept Mech Engn, Oita 8701192, Japan

[2] Korea Inst Mat Sci, Struct Mat Div, Chang Won 642831, South Korea

[3] Gyeongsang Natl Univ, ReCAPT, Dept Mat Sci & Engn, Chinju 660701, South Korea

[4] Changwon Natl Univ, Dept Met & Adv Mat Engn, Chang Won 641773, South Korea

来源：

ENGINEERING FRACTURE MECHANICS | 2017年 / 182卷

基金：

新加坡国家研究基金会; 日本学术振兴会;

关键词：

Fatigue; Crack growth rate; Stress intensity factor; Mixed mode; Equal channel angular pressing; ULTRAFINE-GRAINED COPPER; SEVERE PLASTIC-DEFORMATION; STRESS INTENSITY FACTORS; AL-MG ALLOY; FATIGUE PROPERTIES; CARBON-STEELS; SHEAR BANDS; MODE-I; BEHAVIOR; FINE;

D O I：

10.1016/j.engfracmech.2017.07.024

中图分类号：

O3 [力学];

学科分类号：

08 ; 0801 ;

摘要：

For low-cycle fatigued, ultrafine grained copper, processed by equal channel angular pressing, a unique crack growth direction, either inclined at 45 degrees or perpendicular to the loading direction, was observed around the circumference of round bar specimens. In addition, the perpendicular cracks showed a 45 degrees deflected crack face toward the center of the specimens. To clarify the growth behavior of such inclined and deflected cracks, the role of the deformation mode at the crack-tip areas was discussed in terms of the surface damage caused by cyclic stressing and the mixed-mode deformation at the crack tips. The preexistent shear-bands/shear-cracks around the crack tips and the in-plane shear-mode deformation at the crack tips assisted the formation of shallow inclined- and deep deflected-cracks. To quantitatively estimate the severity of mechanical damage at the crack tips, the comparative stress intensity factor range under combined mode I, II and III conditions were calculated. The crack growth rate along the growth direction at the surface and bottom for inclined and deflected surface-cracks was discussed in terms of the comparative stress intensity factor range. (c) 2017 Elsevier Ltd. All rights reserved.

引用

页码：100 / 113

页数：14

共 59 条

[1] Cyclic softening of ultrafine grain copper [J].