scholarly journals Essential work of fracture, crack tip opening displacement, and J-integral relationship for a ductile polymer film

2016 ◽  
Vol 55 ◽  
pp. 247-256 ◽  
Author(s):  
A.B. Martínez ◽  
N. León ◽  
D. Arencón ◽  
M. Sánchez-Soto
Keyword(s):  
Polymer Film ◽  
J Integral ◽  
Essential Work ◽  
Crack Tip Opening Displacement ◽  
Opening Displacement ◽  
Essential Work Of Fracture ◽  
Fracture Crack ◽  
Ductile Polymer ◽  
Crack Tip Opening ◽  
Work Of Fracture

Essential work of fracture analysis of the tearing of a ductile polymer film

2010 ◽  
Vol 77 (14) ◽  
pp. 2654-2661 ◽  
Author(s):  
A.B. Martínez ◽  
A. Segovia ◽  
J. Gamez-Perez ◽  
M.Ll. Maspoch
Keyword(s):  
Polymer Film ◽  
Fracture Analysis ◽  
Essential Work ◽  
Essential Work Of Fracture ◽  
Ductile Polymer ◽  
Work Of Fracture

Fracture Toughness of PC and PC/ABS Alloy

2008 ◽  
Vol 33-37 ◽  
pp. 567-572
Author(s):  
Hui Min Li ◽  
Qin Zhi Fang ◽  
Tie Jun Wang
Keyword(s):  
Fracture Toughness ◽  
Essential Work ◽  
Crack Tip Opening Displacement ◽  
Opening Displacement ◽  
Critical Crack ◽  
Simple Method ◽  
Double Edge ◽  
Crack Tip Opening ◽  
Fracture Measurement ◽  
Work Of Fracture

As a direct and simple method, essential work of fracture has been widely used for fracture measurement of ductile polymers. In this paper, fracture toughness of PC and PC/ABS alloy is experimentally investigated. A series of double edge-notched tension (DENT) specimens and essential work method are employed to measure the fracture toughness of PC and PC/ABS alloy. By the way, the critical crack tip opening displacement is obtained. Moreover, the fracture surfaces of DENT specimens are examined by using a scanning electron microscope (SEM).

Study of Constraint Issues in Elasto-Plastic Fracture Analysis Using Experimental and Finite Element Simulation

2017 ◽  
Author(s):  
Md Ibrahim Kittur ◽  
Krishnaraja G. Kodancha ◽  
C. R. Rajashekar
Keyword(s):  
Finite Element ◽  
Mild Steel ◽  
Compact Tension ◽  
Specimen Thickness ◽  
J Integral ◽  
Crack Tip Opening Displacement ◽  
Opening Displacement ◽  
3D Fea ◽  
The Comparative Study ◽  
Crack Tip Opening

In this investigation, the variation of J-integral considering Compact Tension (CT) specimen geometry varying a/W and σ using 2D and 3D elasto-plastic Finite Element (FE) analysis have been studied. Further, the investigation has been done to examine the relationship between the J and δ for varied a/W and σ. The plane stress and plane strain elasto-plastic FE analyses have been conducted on the CT specimen with a/W = 0.45–0.65 to extract the J and Crack-tip Opening Displacement (CTOD) values for mild steel. The comparative study of the variation of dn with a/W of mild steel with earlier results of IF steel is carried out. The study clearly infers the effect of yield stress on the variation of the magnitude of dn with reference to a/W ratio. The present analysis infers that while converting the magnitude of the CTOD to J one needs to carefully evaluate the value of dn depending on the material rather than considering it to be unity. Further, the study was extended to experimental and 3D FEA wherein J-integral and CTOD were estimated using the CT specimen. Experimental results reveal that the crack length, the specimen thickness, and the loading configuration have an effect on the fracture toughness measurements. The error analysis between the results obtained by 3D FEA and experimentation were conducted and found to be within limits.

The Inelastic Line-Spring: Estimates of Elastic-Plastic Fracture Mechanics Parameters for Surface-Cracked Plates and Shells

1981 ◽  
Vol 103 (3) ◽  
pp. 246-254 ◽  
Author(s):  
D. M. Parks
Keyword(s):  
Fracture Mechanics ◽  
Crack Growth ◽  
Computing Time ◽  
Crack Tip ◽  
J Integral ◽  
Crack Tip Opening Displacement ◽  
Opening Displacement ◽  
Elastic Plastic ◽  
Plates And Shells ◽  
Crack Tip Opening

Recent studies of the mechanics of elastic-plastic and fully plastic crack growth suggest that such parameters as the J-integral and the crack tip opening displacement can, under certain conditions, be used to correlate the initiation and early increments of the ductile tearing mode of crack growth. To date, elastic-plastic fracture mechanics has been applied mainly to test specimen geometries, but there is a clear need for developing practical analysis capabilities in structures. In principle, three-dimensional elastic-plastic finite element analysis could be performed, but, in fact, such analyses would be prohibitively expensive for routine application. In the present work, the line-spring model of Rice and Levy [1-3] is extended to estimate the J-integral and crack tip opening displacement for some surface crack geometries in plates and shells. Good agreement with related solutions is obtained while using orders of magnitude less computing time.

Strain-Based CTOD and J-Integral Estimations for Pipelines With a Surface Crack Under Large Plastic Strain and Internal Pressure

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Youn-Young Jang ◽  
Ju-Yeon Kang ◽  
Nam-Su Huh ◽  
Ik-Joong Kim ◽  
Young-Pyo Kim
Keyword(s):  
Internal Pressure ◽  
Surface Crack ◽  
Material Properties ◽  
J Integral ◽  
Crack Tip Opening Displacement ◽  
Large Plastic Strain ◽  
Opening Displacement ◽  
Definition Of ◽  
Crack Tip Opening ◽  
Tensile Strain Capacity

Abstract Engineering solutions for crack-tip opening displacement (CTOD) and J-integral estimations for pipelines with a surface crack are proposed based on parametric finite element (FE) analyses for various geometries, material properties, and internal pressure conditions. Two kinds of CTOD definitions are considered in relation to strain-based estimation solutions for dealing with confusion regarding the definition of CTOD and to extend the applicability of tensile strain capacity (TSC) assessment. Moreover, influence functions of internal pressure are also suggested to take account of the effect of internal pressure on TSC. Using the proposed solutions, TSCs for cracked X65 and X70 pipes were assessed based on initiation and ductile instability. Curved wide plate tests were performed to obtain experimental TSCs, which were compared with those from the proposed solutions. Moreover, TSCs from the proposed solutions were also compared with those from other TSC-predicted models in order to assess their validity.

Comparison of Flaw Driving Force Estimates in Simulated Weld Residual Stress Fields

2013 ◽  
Author(s):  
David J. Dewees ◽  
Robert H. Dodds
Keyword(s):  
Residual Stress ◽  
Driving Force ◽  
Three Dimensional ◽  
Crack Size ◽  
J Integral ◽  
Crack Tip Opening Displacement ◽  
Opening Displacement ◽  
Weld Residual Stress ◽  
Future Work ◽  
Crack Tip Opening

Previous work has focused on the methods and results for calculating flaw driving force in simulated three-dimensional (3D) weld residual stress (WRS) fields using contour (J) integral techniques. This paper extends that work to look at explicit modeling of the crack tip opening displacement (CTOD) in these same WRS fields, and for the same range of semi-elliptical flaws. Comparison is made between the predicted trends of driving force with crack size for the calculated driving force (J-integral) versus the “measured” value (CTOD). Implications for fracture assessments are given, and recommendations for future work are made.

Evaluation of CTOD Resistance Curve Test Methods Using SENT Specimens

2016 ◽  
Author(s):  
Xian-Kui Zhu ◽  
Paul Zelenak ◽  
Tom McGaughy
Keyword(s):  
Pipeline Steel ◽  
Test Methods ◽  
J Integral ◽  
Crack Tip Opening Displacement ◽  
Opening Displacement ◽  
Gas Industry ◽  
Offshore Pipelines ◽  
Resistance Curves ◽  
Plastic Parts ◽  
Crack Tip Opening

Single edge-notched tension (SENT) specimens in clamped end conditions are widely adopted in the oil/gas industry to measure fracture resistance curves in terms of the J-integral or crack-tip opening displacement (CTOD) for the strain-based design and crack assessment of onshore and offshore pipelines. Typical CTOD-R curve test methods developed for SENT specimens include CanMet, ExxonMobil, and BS 8571 methods. While CanMet determines CTOD using the J-integral conversion method via one clip gage measurement, the other two infer CTOD directly from double clip gage measurements. ExxonMobil simply uses the total measured displacements to calculate CTOD, but BS 8571 separates CTOD into elastic and plastic parts to be determined, respectively, from the elastic K factor and the plastic component of measured displacements. It is unknown if these CTOD test methods determine comparable R-curves for a same SENT test, and what are the differences between these CTOD test methods. To answer those questions, this paper performs an experimental evaluation of the SENT CTOD test methods. A set of clamped SENT specimens are tested for pipeline steel X80 and structural steel A36. For each SENT test, the unloading compliance method and the double clip gage arrangement are used, and then CTOD-R curves obtained by different methods are evaluated. Evaluation results and conclusions are given for those SENT CTOD test methods.

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