The impact of double dents on pipeline integrity

Student thesis: Master's Thesis

Abstract

Pipelines are used for the transportation of various products across the world. Most of these pipelines are installed underground, which makes it harder to detect a failure or to repair the pipeline when it is damaged. A dent is defined as a plastic deformation in a pipeline which can turn into a threat by causing stress concentration, and as a result the pipeline may fail, which can result in safety, economic and environmental disasters. Guidance is therefore needed for operators to identify which dents could potentially be damaging to pipeline safety and to consider which dents require further action such as excavation or repairing.Experimental research on dents on a pipeline has been made for decades. To understand the severity of such defects on pipelines, various methodologies related to dent assessment have been developed based on the results of experimental studies as well as Finite Element Analysis (FEA).Although many studies have been conducted on a single dent defects, there is no published guidance or assessment methods to determine the severity of multiple dent defects when they are detected in pipelines because current assessment methods or published guidelines treat dents as isolated defect which does not consider interactions with each other. Understanding and predicting the behaviour of pipelines that are subjected to a multiple dents will require an assessment to determine how severe the effect could be.Analysis was carried with three standard parameters; dent depth, effects of distance between the dents and effects of indenter diameters. The objective for this study is to create a Finite Element Model (FEM) to develop a parametric study to determine interaction effect of each dents considering the dent shape, distance between the dents and the effect of internal pressure.
Date of Award1 Jun 2018
Original languageEnglish
Awarding Institution
  • University Of Strathclyde
SupervisorJulia Race (Supervisor) & Selda Oterkus (Supervisor)

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