Fracture Behavior Estimation for Circumferential Surface Cracked Pipes (I) - J-Integral Estimation Solution -

2002 ◽  
Vol 26 (1) ◽  
pp. 131-138
Author(s):  
Jin-Su Kim ◽  
Yun-Jae Kim ◽  
Yeong-Jin Kim
Keyword(s):  
Fracture Behavior ◽  
J Integral ◽  
Integral Estimation

scholarly journals Evaluation of J-integral estimation procedures.

1987 ◽  
Vol 36 (403) ◽  
pp. 334-340
Author(s):  
Kenji HAYASHI ◽  
Hiromasa KAWAMURA ◽  
Kohsuke HORIKAWA
Keyword(s):  
J Integral ◽  
Estimation Procedures ◽  
Integral Estimation

Finite Element Fracture Mechanics Study of Pre-Northridge Connections

2006 ◽  
Vol 324-325 ◽  
pp. 1007-1010 ◽  
Author(s):  
Hong Bo Liu ◽  
Chang Hai Zhai ◽  
Yong Song Shao ◽  
Li Li Xie
Keyword(s):  
Stress Intensity Factor ◽  
Finite Element ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Fracture Behavior ◽  
Integral Approach ◽  
J Integral ◽  
Finite Element Analyses ◽  
Element Analysis ◽  
Weld Root

The objective was to quantify the variation of stress intensity factor to weld root flaw sizes in steel frame connections. Finite-element analyses were used to study fracture toughness in welded beam-column connections. Investigations of fracture behavior mainly focused on the standard pre-Northridge connection geometry. Finite element analysis was performed using the ANSYS computer program. Stress intensity factor was calculated through a J-integral approach. Results show that stress intensity factor is not uniform and is largest in the middle of beam flange. Stress intensity factor increases nearly linear with the increase of flaw size. Backing bars have little effect on weld fractures.

A review of fatigue and fracture mechanics with a focus on rubber-based materials

2017 ◽  
Vol 233 (5) ◽  
pp. 1005-1019 ◽  
Author(s):  
Pooya Behroozinia ◽  
Reza Mirzaeifar ◽  
Saied Taheri
Keyword(s):  
Finite Element ◽  
Fracture Mechanics ◽  
Strain Energy ◽  
Strain Energy Release ◽  
Fatigue Loading ◽  
J Integral ◽  
Element Analysis ◽  
Integral Estimation ◽  
Primary Focus ◽  
Energy Dissipated

Prediction of how cracks nucleate and develop is a major concern in fracture mechanics. The purpose of this study is to provide an overview of the state of the art on fracture mechanics with primary focus on different methodologies available for crack initiation and growth prediction in rubber-based materials under the static and fatigue loading conditions. The concept of fracture mechanics applied to rubber-based materials and concern of finite element analysis for J-integral estimation in elastomers are discussed in this paper. The strain energy release rate is commonly used to describe the energy dissipated during fracture per unit of fracture surface area and can be calculated by J-integral method, which represents a path-independent integral around the crack tip. As fatigue crack growth most commonly occurs in structures, the high-cycle fatigue life of components needs to be predicted by using extended finite element, strain energy density, finite fracture mechanics, and other techniques which will be covered in this review paper. In addition, some recent testing and numerical results reported in the literature and their applications will be discussed.

Estimation Method for Evaluating Energy Release Rate of Circumferential Through-Wall Cracks in Dissimilar Metal Welds

2015 ◽  
Author(s):  
Jeong Soon Park ◽  
Richard Olson
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Estimation Method ◽  
New Method ◽  
Estimation Methods ◽  
J Integral ◽  
Mixture Ratio ◽  
Dissimilar Metal ◽  
Integral Estimation

In this study, an estimation method is proposed to evaluate the energy release rate (J-integral) of a circumferential through-wall crack in a dissimilar metal (DM) weld subjected to tension and/or bending. In order to evaluate such cracks in a DM weld, the concept of a mixture ratio has been introduced, so that the existing single-material J-integral estimation method can be utilized with effective material strength properties which are the mixture of the two base metal properties with some ratio. The mixture ratio, however, is empirical, and several numerical analyses would be required to determine an appropriate value of mixture ratio. The new J-integral estimation method proposed in this study can take account of three material properties of the two base metals and a weld metal. Following the approach similar to the LBB.ENG2 method, the new method provides closed-form solutions for the J-integral by introducing an equivalent reduced thickness section replacing the cracked section in the DM weld. It is confirmed that the new method successfully degenerates to the existing one- and two-material J-estimation methods, when simulating one- and two-material crack problems. Furthermore, the maximum moments predicted by the proposed method, as a result of crack stability analyses, show good agreements with DM weld test results.

Evaluation of Elasto-Plastic Interfacial Fracture Parameters in Solder-Copper Bimaterial Using Moire´ Interferometry

1998 ◽  
Vol 120 (3) ◽  
pp. 267-274 ◽  
Author(s):  
H. Krishnamoorthy ◽  
H. V. Tippur
Keyword(s):  
Crack Opening ◽  
Moiré Interferometry ◽  
Initiation Toughness ◽  
Moire Interferometry ◽  
Fracture Parameter ◽  
J Integral ◽  
Single Strain ◽  
Full Field ◽  
Integral Estimation ◽  
Crack Tip Opening

An experimental investigation dealing with failure characterization of 63/37 solder-copper interfaces is presented. The method of moire´ interferometry is used for mapping elasto-plastic deformations in bimaterials subjected to predominantly tensile loading. A method for quantifying the fracture parameter—the J-integral—using full-field measurement of crack opening displacements has been developed. A linear relationship between crack tip opening displacements (CTOD) and the J-integral is demonstrated. The crack growth resistance curve and hence crack initiation toughness Jc value for the bimaterial is obtained. Full-field optical information has also suggested the possibility of using a simpler method for the J-integral estimation using a single strain gage for fracture testing of interfaces with large mismatch in this geometry.

Finite Element Analysis for J-Integral of Axial Through-Wall Cracked Elbow Under Bending Moment

2011 ◽  
Author(s):  
Wei-Ju Liu ◽  
Bor-Jiun Tsai ◽  
Jien-Jong Chen ◽  
Yan-Shiun Du ◽  
Wei-Sheng Liu
Keyword(s):  
Finite Element ◽  
Fracture Behavior ◽  
Bending Moment ◽  
Element Model ◽  
J Integral ◽  
Element Analysis ◽  
Linear Deformation ◽  
Proposed Model ◽  
Non Linear ◽  
Leak Before Break

Leak-before-break (LBB) assessment of nuclear piping involves ductile fracture analysis of pipes or elbows with postulated through-wall cracks. Due to the fact that the crown part of an elbow is one of the positions that crack initiation occurs in most frequently, the calculation of J-integrals to investigate fracture behavior are important research topics. This paper proposes a 3-D finite element model of an elbow embedded with an axial through-wall crack to estimate the J-integral parameters under bending moment. The J-integral values can be calculated by using ABAQUS and taking into account the effects of geometrical and model of material in non-linear analysis. The results show that the non-linear deformation and contact condition of crack surfaces play important roles for the J-integral values. In addition, the J values estimated by the proposed model are more conservative and realistic than previous studies.

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