Issue 58

A. I. Fezazi. et alii, Frattura ed Integrità Strutturale, 58 (2021) 231-241; DOI: 10.3221/IGF-ESIS.58.17

Numerical prediction of the ductile damage for axial cracks in pipe under internal pressure

Fezazi Amina Ismahène, Mechab Belaïd, Salem Mokadem, Serier Boualem University of Djillali Liabes, LPMM Laboratory, SidiBel Abbes, Algeria fezaziismahane223@gmail.com, bmechab@yahoo.fr, moka_salem@yahoo.fr, boualems@yahoo.fr

A BSTRACT . This study presents a numerical prediction of the ductile damage for axial cracks in pipe subjected to internal pressure. The three dimensional finite element methods used to evaluate the J-integral. The effect of the external radius (R ext ), thickness of the pipe (t), length crack (a), applied loads (P) and crack position has studied. The Monte Carlo method was used to determine the probabilistic characteristics of the J-integral. It’s also used later to predict the failure probability based on initiation of the crack growth. We note that the crack size and the geometries of the pipe are an important factor influencing on the durability of the pipe. K EYWORDS . Failure; Pipe; Fracture mechanics; Monte Carlo method.

Citation: Fezazi, A. I., Mechab, B., Salem, M., Serier, B., Numerical prediction of the ductile damage for axial cracks in pipe under internal pressure, Frattura ed Integrità Strutturale, 58 (2021) 231-241.

Received: 19.05.2021 Accepted: 26.07.2021 Published: 01.10.2021

Copyright: © 2021 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

I NTRODUCTION

P

ipelines have been built to transport many other fluids (liquids and gases). For instance, liquid fertilizers are often transported long distances via pipelines. The mixture of oil and natural gas coming out of a well must be transported as two-phase flow by pipelines to processing facilities before the oil can be separated from the gas. The fracture prediction and the reliability of such piping systems in various practical applications are primordial given their impact on the economic plan and security [1-4]. Several authors have been studied pipe fracture problems by means of numerical simulation in order to assess the mechanical integrity, taking into account different crack shapes [5-7]. The ductile fracture mechanics parameters for the cracked pipes subjected to internal pressure is important in structural integrity assessment of defective components [8-10]. The safety assessment of these structures and the comprehension of failure mechanisms are essential to study the reliability of pipelines for the liquid or gas transport [11-14]. Probabilistic fracture mechanics is a means of quantifying the failure probability resulting from uncertainties in the values of the parameters used to perform a failure assessment of cracked structures through probabilistic analysis techniques [15- 17]. Rahman [18] analyzed small cracks in tubes under internal pressure and bending loads, where one of the observations was that for through-wall-thickness cracks the effect of internal pressure was significant for high-

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