J-Integral Calculation by Finite Element Processing of Measured Full-Field Surface Displacements

Electrofusion joint plays an important role in connecting polyethylene (PE) pipe. In our previous study, penetrating crack failure through the fitting with an angle of about 70° was observed, and axial stress was found to be an important factor in the crack propagation. In this paper, experiments were carried out to study the crack propagation phenomena of the electrofusion joint of PE pipe. Digital Image Correlation (DIC) method was used to measure the displacement on specimen’s surface, as well as full-field strain distribution, based on which the J-integral of the crack tip was calculated. Besides, a finite element numerical simulation was conducted, and its accuracy was verified by experimental J-integral value. Through combination of experimental observations and finite element method, the phenomenon that the angle between crack propagation direction and tube axial is about 70° is detailed analysed. By comparison and analysis of the testing results, critical J-integral value during crack propagation is determined. Furthermore, critical J-integral value of crack propagation in electrofusion joint is predicted.

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Thermo-responsive and shape-morphing CF/GF composite skin: Full-field experimental measurement, theoretical prediction, and finite element analysis

Thin-Walled Structures ◽

10.1016/j.tws.2020.106874 ◽

2021 ◽

Vol 160 ◽

pp. 106874

Author(s):

Jamal Seyyed Monfared Zanjani ◽

Pouya Yousefi Louyeh ◽

Isa Emami Tabrizi ◽

Abdulrahman Saeed Al-Nadhari ◽

Mehmet Yildiz

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Theoretical Prediction ◽

Experimental Measurement ◽

Element Analysis ◽

Full Field ◽

Shape Morphing

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Elastic-Plastic Analysis of an Elbow With Axial Part-Through Internal Crack at Crown Under In-Plane Bending

Volume 3: Design and Analysis ◽

10.1115/pvp2008-61452 ◽

2008 ◽

Author(s):

K. M. Prabhakaran ◽

S. R. Bhate ◽

V. Bhasin ◽

A. K. Ghosh

Keyword(s):

Finite Element ◽

Crack Depth ◽

Bending Moment ◽

Internal Crack ◽

J Integral ◽

Finite Element Analyses ◽

Integrity Assessment ◽

Elastic Plastic ◽

Axial Part ◽

Plane Bending

Piping elbows under bending moment are vulnerable to cracking at crown. The structural integrity assessment requires evaluation of J-integral. The J-integral values for elbows with axial part-through internal crack at crown under in-plane bending moment are limited in open literature. This paper presents the J-integral results of a thick and thin, 90-degree, long radius elbow subjected to in-plane opening bending moment based on number of finite element analyses covering different crack configurations. The non-linear elastic-plastic finite element analyses were performed using WARP3D software. Both geometrical and material nonlinearity were considered in the study. The geometry considered were for Rm/t = 5, and 12 with ratio of crack depth to wall thickness, a/t = 0.15, 0.25, 0.5 and 0.75 and ratio of crack length to crack depth, 2c/a = 6, 8, 10 and 12.

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

Volume 7A: Structures and Dynamics ◽

10.1115/gt2017-63871 ◽

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.

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