J-integral estimation by reference plastic slope method for poly-linear stress-strain curves

2021 ◽  
Vol 191 ◽  
pp. 104366
Author(s):  
Masayuki Kamaya
Keyword(s):  
J Integral ◽  
Stress Strain ◽  
Slope Method ◽  
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

Deformation Plasticity Failure Assessment Diagram (DPFAD) for Materials With Non-Ramberg-Osgood Stress-Strain Curves

1995 ◽  
Vol 117 (4) ◽  
pp. 346-356 ◽  
Author(s):  
J. M. Bloom
Keyword(s):  
Tensile Stress ◽  
Manganese Steel ◽  
Uniaxial Tensile ◽  
J Integral ◽  
Stress Strain ◽  
Failure Assessment Diagram ◽  
Failure Assessment ◽  
Strain Data ◽  
Deformation Plasticity ◽  
Uniaxial Tensile Stress

This paper presents a brief history of the evolution of the Central Electricity Generating Board’s (CEGB) R-6 failure assessment diagram (FAD) procedure used in assessing defects in structural components. The reader is taken from the original CEGB R-6 FAD strip yield model to the deformation plastic failure assessment diagram (DPFAD), which is dependent on Ramberg-Osgood (R-O) materials to general stress-strain curves. An extension of the DPFAD approach is given which allows the use of material stress-strain data which do not follow the R-O equation such as stainless steel or carbon manganese steel. The validity of the new approach coined piecewise failure assessment diagram (PWFAD) is demonstrated through comparisons with the J-integral responses (expressed in terms of failure assessment diagram curves) for several cracked configurations of non-R-O materials. The examples were taken from both finite element and experimental results. The comparisons with these test cases demonstrate the accuracy of PWFAD. The use of PWFAD requires the availability of deformation plasticity J-integral solutions for several values of the strain-hardening exponent as well as uniaxial tensile stress-strain data at the temperature of interest. Lacking this information, the original R-O DPFAD approach using known engineering yield and ultimate strengths would give the best available approximation. However, it is strongly recommended that actual uniaxial tensile stress-strain data be used when available.

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.

Effect of Biaxial Stress on Crack Driving Force

2006 ◽  
Author(s):  
G. Shen ◽  
W. R. Tyson
Keyword(s):  
Internal Pressure ◽  
Driving Force ◽  
Axial Stress ◽  
Axial Strain ◽  
Biaxial Stress ◽  
J Integral ◽  
Longitudinal Stress ◽  
Secondary Stress ◽  
Stress Strain ◽  
Strain Equation

A stress-strain equation of Ramberg-Osgood type is proposed to correlate the longitudinal stress with longitudinal strain of a thin plate when a constant stress is applied transversely. The same approach can be used to correlate the axial stress with axial strain for a thin-walled pipe in axial tension with internal pressure. The proposed stress-strain equation relating the longitudinal stress and strain closely approximates that of deformation theory. The effect of a secondary stress (hoop stress) on the J-integral for a circumferential crack in a pipe under axial load and internal pressure is evaluated by finite element analysis (FEA). The results show that the J-integral decreases with internal pressure at a given axial stress but increases with internal pressure at a given axial strain. It is concluded that while a secondary stress may be safely neglected in a stress-based format because it decreases the driving force at a given applied stress, it should not be neglected in a strain-based format because it significantly increases the driving force at a given applied strain.

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.

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