Strain Localization in the Dent of a Linepipe

2014 ◽  
Author(s):  
Jandark Oshana-Jajo ◽  
Hossein Ghaednia ◽  
Jamshid Zohreh Heydariha ◽  
Sreekanta Das
Keyword(s):  
Finite Element ◽  
Oil And Gas ◽  
Finite Element Analyses ◽  
Remedial Action ◽  
Line Pipe ◽  
Engineering Research ◽  
Element Simulation ◽  
Prime Objective ◽  
Full Scale Tests ◽  
Pipeline Wall

Steel pipelines used for transporting oil and gas can develop various damages such as mechanical damages, corrosion, wrinkle, and crack. One of the mechanical damages is a dent with or without other defects such as corrosion, gouge, and crack. The dent without other defect is often referred to as plain dent. Depending on the severity, a dent can lead to a failure of a field linepipe. The strain concentration in a dented pipeline wall can be used to determine the level of severity of a dent. Hence, a research program was undertaken at the Centre for Engineering Research in Pipelines (CERP) using full-scale tests and finite element analyses. The prime objective of this research was to determine comparative strain distributions in and around the dent and locations of high strains developed from the denting process. This information will help the pipeline operators to determine the severity of dents in their field linepipes. Hence, the outcome of this research will allow the pipeline operators to take an informed decision on whether or not an imminent remedial action for the dented segment of the line pipe is required. This paper presents test data and finite element simulation to discuss the locations and values of crucial strains in dents.

Buckling Resistance of Large Diameter Spiral Welded Linepipe

2004 ◽  
Author(s):  
Tom Zimmerman ◽  
Chris Timms ◽  
Jueren Xie ◽  
James Asante
Keyword(s):  
Oil And Gas ◽  
Weld Seam ◽  
Large Diameter ◽  
Ground Movement ◽  
Finite Element Analyses ◽  
Line Pipe ◽  
Diameter Pipe ◽  
Buckling Resistance ◽  
Analytical Research ◽  
Full Scale Tests

This paper contains the results of an experimental and analytical research program to determine the compressive buckling resistance of large-diameter, spiral-welded linepipe. Buckling resistance is important for pipe intended for service in Arctic, oil and gas pipeline systems, where pipes may be subjected to high bending strains caused by various ground movement events. The experimental work consisted of four full-scale tests of 30-inch (762 mm) diameter pipe subjected to various combinations of internal pressure, axial force and bending. The pipe specimens were fabricated using two material grades (X70 and X80) and two D/t ratios (82 and 48). Finite element analyses of the four tests were conducted to develop a better understanding of specimen behavior. The results suggest that spiral welded linepipe is as good as longitudinally welded line pipe in terms of buckling capacity. The spiral weld seam was in no way detrimental to the pipe performance.

Investigation on endurance evaluation of a portal crane: experimental, theoretical and finite element analysis

2020 ◽  
Vol 62 (4) ◽  
pp. 357-364
Author(s):  
Yusuf Aytaç Onur ◽  
Hakan Gelen
Keyword(s):  
Finite Element ◽  
Critical Points ◽  
Maximum Stress ◽  
Strain Gages ◽  
Finite Element Analyses ◽  
Element Analysis ◽  
Element Simulation ◽  
Main Girder ◽  
Stressed Component ◽  
Portal Crane

Abstract In this study, the stress on portal crane components at various payloads has been investigated theoretically, numerically and experimentally. The portal crane was computer-aided modeled and finite element analyses were performed so that the most stressed points at the each trolley position investigated on the main girder could be determined. In addition, the critical points were marked on the portal crane, and strain gages were attached to the those critical points so that stress values could be experimentally determined. The safety factor values at different payloads were determined by using finite element simulation. Results indicate that the most stressed component in the examined portal crane is the main girder. Experimental results indicate that the maximum stress value on the main girder is 3.05 times greater than the support legs and 8.99 times larger than the rail.

Finite Element Analysis of Creep Induced Volume Shrinkage of Salt Caverns

2013 ◽  
Vol 353-356 ◽  
pp. 1379-1385
Author(s):  
Ming Zhang ◽  
Shao Xin Zhang ◽  
Qiang Yang
Keyword(s):  
Finite Element ◽  
Oil And Gas ◽  
Volume Shrinkage ◽  
Salt Rock ◽  
Simplified Models ◽  
Element Analysis ◽  
Element Simulation ◽  
Storage Volume ◽  
The Stability ◽  
Salt Caverns

Salt rock is now being used widely as storage vault of oil and gas. However, the rheological properties of salt rock have significant influence on the stability of salt caverns and, in particular, induce the reduction of storage volumes. Therefore, the classical Nishihara model is used to describe the rheology of salt rock and incorporated into the finite element simulation firstly. Then the volume shrinkage is calculated for two typical simplified models with single cavern and double caverns. The results show that the storage volume of salt cavern decreases with the internal pressure and increases with service time for either single-cavern model or double-cavern model, which remains unchanged though the volume shrinkage of one cavern is influenced by others.

scholarly journals Finite element modeling of nanoindentation on an elastic-plastic microsphere

2020 ◽  
Author(s):  
Jialian Chen ◽  
Hongzhou Li
Keyword(s):  
Finite Element ◽  
Mechanical Behavior ◽  
Computational Study ◽  
Theoretical Method ◽  
Finite Element Analyses ◽  
Structured Materials ◽  
Elastic Plastic ◽  
Element Simulation ◽  
Insight Into

Abstract The understanding of the mechanical indentation on a curved specimen (e.g., microspheres and microfibers) is of paramount importance in the characterization of curved micro-structured materials, but there has been no reliable theoretical method to evaluate the mechanical behavior of nanoindentation on a microsphere. This article reports a computational study on the instrumented nanoindentation of elastic-plastic microsphere materials via finite element simulation. The finite element analyses indicate that all loading curves are parabolic curves and the loading curve for different materials can be calculated from one single indentation. The results demonstrate that the Oliver-Pharr formula is unsuitable for calculating the elastic modulus of nanoindentation involving cured surfaces. The surface of the test specimen of a microsphere requires prepolishing to achieve accurate results of indentation on a micro-spherical material. This study provides new insight into the establishment of nanoindentation models that can effectively be used to simulate the mechanical behavior of a microsphere.

Effect of Material Stress-Strain Behavior and Pipe Geometry on the Deformability of High-Grade Pipelines

2004 ◽  
Vol 126 (1) ◽  
pp. 113-119 ◽  
Author(s):  
Hiroshi Yatabe ◽  
Naoki Fukuda ◽  
Tomoki Masuda ◽  
Masao Toyoda
Keyword(s):  
Finite Element ◽  
High Grade ◽  
Finite Element Analyses ◽  
Analysis Method ◽  
Element Analysis ◽  
Line Pipe ◽  
Strain Behavior ◽  
Parametric Studies ◽  
Pipe Geometry ◽  
Strain Hardening Behavior

In this study, the deformability of high-grade pipelines subjected to an axial compressive deformation was experimentally and analytically discussed. Six cases of axial compression experiments with high-grade line pipe were carried out. The pipe specimens had various material properties and wall thickness. Finite-element analyses were also carried out and verified the reliability. Then, a finite-element analysis method for evaluating the deformability of the line pipe was established. By using this method, parametric studies were carried out. The effects of the strain-hardening behavior and pipe geometry on the deformability of the high-grade pipelines were examined.

Implementation of Finite-Element Codes for the Simulation of Ship-Ship Collisions*

2002 ◽  
Vol 46 (04) ◽  
pp. 239-247
Author(s):  
Dimitris Servis ◽  
Manolis Samuelides ◽  
Tina Louka ◽  
Giorgos Voudouris
Keyword(s):  
Finite Element ◽  
Automotive Industry ◽  
Structural Elements ◽  
Finite Element Analyses ◽  
Engineering Research ◽  
Effective Implementation ◽  
The Past ◽  
Research Areas ◽  
Considerable Success ◽  
Impact Problems

The problem of ship collisions may well be considered one of the most complicated impact problems that contemporary engineering research is encountering. The structures involved are very large and include various structural elements. Thus, there is a large number of different modes of deformation that may occur, a fact that introduces a lot of parameters in the investigation of such problems. Finite-element analyses have been used over the past decade to solve several impact problems effectively. Though considerable success has been recorded in many research areas, such as the automotive industry, ship collision simulations still confront diffculties culties in providing reliable results. This paper attempts to determine the parameters that largely influence ship collisions and to provide tools and guidelines for the effective implementation of finite-element codes.

Local Buckling Assessments for the Medgaz Pipeline

2007 ◽  
Author(s):  
D. DeGeer ◽  
C. Timms ◽  
J. Wolodko ◽  
M. Yarmuch ◽  
R. Preston ◽  
...  
Keyword(s):  
Finite Element ◽  
Gas Flow ◽  
Local Buckling ◽  
External Pressure ◽  
Full Scale ◽  
Regression Equations ◽  
Finite Element Analyses ◽  
Bending Strain ◽  
Primary Focus ◽  
Full Scale Tests

Medgaz is a consortium of leading international energy companies, with the aim of designing, building and operating an Algerian-European gas pipeline via Spain. The offshore section of this pipeline will be 210 km long, traversing the Mediterranean Sea floor at a maximum depth of 2160 metres. The 24-inch diameter, grade X70 line will provide up to 8 billion cubic metres of natural gas per year, with first gas flow expected in 2009. To support the technical issues surrounding such an ultra-deepwater pipelay, a number of full scale local buckling tests and detailed finite element analyses were undertaken at the C-FER facility in Edmonton, Canada. Local buckling conditions of concern included buckling of the pipe section at the pipe-buckle arrestor interface and collapse of the plain pipe under high external pressure. These conditions may arise during various phases of pipeline installation and operation, but the primary focus was to evaluate the local buckling integrity of the pipe during installation using the S-lay method. These conditions were assessed for both as-fabricated pipe and pipe that was heat treated to simulate a pipe coating process. This paper describes the Medgaz pipeline, its current state of development, the installation challenges that necessitated the buckling assessments, and some of the work performed throughout the study, including full scale tests, finite element analyses, and regression analyses. Collapse and critical bending strain predictive equations were developed and are also presented, and are compared to other well known collapse and critical bending strain equations. The results of these assessments have suggested that, for the local buckling conditions presented herein, the S-lay method can be successfully employed for ultra-deep water pipelay. The results demonstrated that the proposed pipe-buckle arrestor connection design will not cause premature buckling as the pipe traverses along the stinger during installation. In addition, potentially high bending strains in the overbend will not significantly influence the collapse strength of the pipe. The regression equations presented in this paper have also been shown to provide an accurate means of predicting pipe local buckling and collapse.

scholarly journals Thermal-Mechanical Coupled Manufacturing Simulation in Heterogeneous Materials

2016 ◽  
Vol 2 (11) ◽  
pp. 600-606 ◽  
Author(s):  
Abdelouahid El Amri ◽  
M. El Yakhloufi Haddou ◽  
A. Khamlichi
Keyword(s):  
Finite Element ◽  
Mechanical Damage ◽  
Numerical Procedure ◽  
Calibration Procedure ◽  
Finite Element Analyses ◽  
Element Simulation ◽  
Proposed Model ◽  
Main Target ◽  
6061 Aluminium Alloy ◽  
Strength And Ductility

This work is aimed to investigate on thermal and thermo-mechanical behaviour of 6061 Aluminium alloy. The main target of the present investigation is to apply a numerical procedure to assess the thermo-mechanical damage. Finite element analyses of the notched tensile specimens at high temperature have been carried out using ABAQUS Software. The objective was to study the combined effects of thermal and mechanical loads on the strength and ductility of the material. The performance of the proposed model is in general good and it is believed that the presented results and experimental–numerical calibration procedure can be used in practical finite-element simulation.

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