Three-dimensional modeling of ductile crack growth: Cohesive zone parameters and crack tip triaxiality

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	Three-dimensional modeling of ductile crack growth: Cohesive zone parameters and crack tip triaxiality
	C. R. Chen; O. Kolednik; J. Heerens; F. D. Fischer
	2005
发表期刊	Engineering Fracture Mechanics
ISSN	0013-7944
卷号	72 期号:13 页码:2072-2094
摘要	For 10 mm thick smooth-sided compact tension specimens made of a pressure vessel steel 20MnMoNi55, the interrelations between the cohesive zone parameters (the cohesive strength, T-max and the separation energy, Gamma) and the crack tip triaxiality are investigated. The slant shear-lip fracture near the side-surfaces is modeled as a normal fracture along the symmetry plane of the specimen. The cohesive zone parameters are determined by fitting the simulated crack extensions to the experimental data of a multi-specimen test. It is found that for constant cohesive zone parameters, the simulated crack extension curves show a strong tunneling effect. For a good fit between simulated and experimental crack growth, both the cohesive strength and the separation energy near the side-surface should be considerably lower than near the midsection. When the same cohesive zone parameters are applied to the 3D model and a plane strain model, the stress triaxiality in the midsection of the 3D model is much lower, the von-Mises equivalent stress is distinctly higher, and the crack growth rate is significantly lower than in the plane strain model. Therefore, the specimen must be considered as a thin specimen. The stress triaxiality varies dramatically during the initial stages of crack growth, but varies only smoothly during the subsequent stable crack growth. In the midsection region, the decrease of the cohesive strength results in a decrease of the stress triaxiality, while the decrease of the separation energy results in an increase of the triaxiality. (c) 2005 Elsevier Ltd. All rights reserved.
部门归属	austrian acad sci, erich schmid inst mat sci, a-8700 leoben, austria. mat ctr, a-8700 leoben, austria. shenyang natl lab mat sci, shenyang 110016, peoples r china. univ sydney, ctr adv mat technol, sch aerosp mech & mechatron engn, sydney, nsw 2006, australia. gkss forschungszentrum geesthacht gmbh, d-21502 geesthacht, germany. austrian acad sci, inst mech, montanuniv leoben, a-8700 leoben, austria.;kolednik, o (reprint author), austrian acad sci, erich schmid inst mat sci, jahnstr 12, a-8700 leoben, austria;kolednik@unileoben.ac.at
关键词	Cohesive Zone Model Ductile Fracture Crack Growth Resistance Stress Triaxiality Fracture Process Zone Thin Aluminum Panels Sheet-metal Fracture Work Resistance Separation Stress Decohesion Simulation Toughness
URL	查看原文
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/34803
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	C. R. Chen,O. Kolednik,J. Heerens,et al. Three-dimensional modeling of ductile crack growth: Cohesive zone parameters and crack tip triaxiality[J]. Engineering Fracture Mechanics,2005,72(13):2072-2094.
APA	C. R. Chen,O. Kolednik,J. Heerens,&F. D. Fischer.(2005).Three-dimensional modeling of ductile crack growth: Cohesive zone parameters and crack tip triaxiality.Engineering Fracture Mechanics,72(13),2072-2094.
MLA	C. R. Chen,et al."Three-dimensional modeling of ductile crack growth: Cohesive zone parameters and crack tip triaxiality".Engineering Fracture Mechanics 72.13(2005):2072-2094.