Fatigue Life Evaluation for the Repair Methods of High Pressure Gas Pipeline

2019 ◽  
Author(s):  
Woo Sik Kim
Keyword(s):  
Finite Element ◽  
High Pressure ◽  
Residual Stresses ◽  
Stress Analysis ◽  
Structural Integrity ◽  
Gas Pipeline ◽  
Optimum Process ◽  
Term Operation ◽  
Steel Sleeve

Abstract High pressure gas pipeline must maintain structural integrity during the design life. To do this, periodic pipeline inspections are carried out, and fitness-for-service assessments are performed on defects found by inspection. Defects that do not meet the evaluation criteria should be repaired and replaced to ensure the integrity of the pipeline structure at the same level as before the defect. High pressure gas pipeline repair method is applied to repair of composite reinforced sleeve and repair of steel sleeve. Although there have been many studies on the short-term structural integrity evaluation of rupture pressure in these repair methods, there is insufficient research to verify whether the long-term operation of the repair pipeline maintains the long-term structural integrity of the repaired pipe. In this study, an optimum process to improve structural integrity was established by investigating effect of the process variables on fatigue lifetime of steel-sleeve repair welds in buried gas pipeline. Residual stresses in the repair welds were derived through sequentially-coupled temperature-stress analysis using ABAQUS, which is a commercial finite element analysis program. In addition, variations of operating stresses were derived by finite element linear elastic stress analysis. Fatigue lifetimes of the steel-sleeve repair welds were evaluated by substituting the derived weld residual stresses and operating stress variations into the structural stress/fracture mechanics approach as input. Appling this method confirms long-term integrity over 200 years in terms of fatigue the abstract here in italics.

Stress Analysis and Strength Checking for High Pressure Gas Pipeline in the Earthquake Rupture Area

2013 ◽  
Vol 470 ◽  
pp. 866-870
Author(s):  
Wei He ◽  
Yan Dong Liu ◽  
Guo Xing Wang
Keyword(s):  
Finite Element ◽  
High Pressure ◽  
Stress Analysis ◽  
Gas Pipeline ◽  
Earthquake Rupture ◽  
Rupture Area ◽  
Pipeline Crossing ◽  
The Way

Based on the actual project example of high pressure gas pipeline crossing earthquake rupture area, the paper shows and explains the way to make stress analysis and strength checking calculation for the high pressure gas pipeline in the earthquake rupture area by the method of finite element.

Integrity Assessment of a Free-Fall Lifeboat Launched From a FPSO

2015 ◽  
Author(s):  
Guomin Ji ◽  
Nabila Berchiche ◽  
Sébastien Fouques ◽  
Thomas Sauder ◽  
Svein-Arne Reinholdtsen
Keyword(s):  
Finite Element ◽  
Pressure Distribution ◽  
Structural Integrity ◽  
Dynamic Effect ◽  
Sensitivity Study ◽  
Computational Time ◽  
Load Factor ◽  
Time Varying ◽  
Integrity Assessment

The paper addresses the structural integrity assessment of lifeboat launched from floating production, storage and offloading (FPSO) vessels. The study is based on long-term drop lifeboat simulations accounting for more than 50 years of hindcast data of metocean conditions and corresponding FPSO motions. Selection of the load cases and strength analyses with high computational time is a challenge. The load cases analyzed are those corresponding to the 99th percentile of long term distribution of indicators for large slamming loads (CARXZ) or large submergence (Imaxsub). For six selected cases, the time-varying pressure distribution on the lifeboat hull during and after water impact is calculated by CFD simulations using StarCCM+. The finite element model (FEM) of the composite structure of the lifeboat is modelled by ABAQUS. Quasi-static finite element (FE) analyses are performed for the selected load cases. The structural integrity is assessed by the maximum stress and Tsai-Wu failure measure. In the present study, the load and resistance factors are combined and applied to the response. A sensitivity study is performed to investigate the non-linear load/response effects when the load factor is applied to the load. In addition, dynamic analysis is performed with the time-varying pressure distribution for selected case and the dynamic effect is investigated.

Evaluation of Residual Stresses in Butt Welded Joint of Dissimilar Material by FEM

2017 ◽  
Vol 754 ◽  
pp. 268-271 ◽  
Author(s):  
Raffaele Sepe ◽  
M. Laiso ◽  
A. de Luca ◽  
Francesco Caputo
Keyword(s):  
Finite Element ◽  
Residual Stresses ◽  
Arc Welding ◽  
Structural Integrity ◽  
Welded Joint ◽  
Dissimilar Material ◽  
Fe Model ◽  
Butt Joints ◽  
Integrity Assessment ◽  
Steel Joints

The study proposed within this paper deals with an application of finite element techniques to the thermo-structural analysis of a dissimilar butt-welded joint. Residual stresses induced by the fusion arc-welding of steel joints in power generation plants are a concern to the industry. Nowadays, the application of finite element method appears to be a very efficient method for the prediction and the investigation of the weld-induced residual stresses, nevertheless the detailed modelling of all phenomena involved in such process is still challenging. The structural integrity assessment of welded structures strongly requires a deep investigation of weld-induced residual stresses in order to be compliant with safety requirement of power plant. The longitudinal and transversal residual stresses in dissimilar material butt joints of 8 mm thick for V-groove shape were studied. The developed thermo-mechanical FE model as well as the simulation procedures are detailed and results are discussed. As a result of such work, it has been found out that residual stresses in the two dissimilar plates are characterized by very different magnitudes and distribution.

Use of Finite-Element Stress Analysis in the Design of a Tank-Cannon-Launched Training Projectile

1994 ◽  
Author(s):  
Michael S. L. Hollis
Keyword(s):  
Finite Element ◽  
Stress Analysis ◽  
Structural Integrity ◽  
Compressive Loading ◽  
Structural Failure ◽  
Finite Element Stress Analysis ◽  
Von Mises ◽  
Current Kinetic ◽  
A Current ◽  
Stress Analyses

Abstract The U.S. Army Armament Research. Development, and Engineering Center (ARDEC) recently expressed a need for a tank-cannon-launched training projectile with reduced penetration capability. The expressed primary design goals for this projectile were to minimize the probability of personnel injury and materiel loss in the event of an accidental impact during a training exercise. In order to meet these design goals, the solid-steel flight body of a current kinetic energy (KE) training projectile, the M865IP, was replaced with a hollow aluminum configuration. Because of the incorporation of aluminum, the structural integrity of the entire projectile during launch was put in question. Thus, a thorough stress analysis of the new design was conducted to alleviate concerns about its structural integrity. Two-dimensional, axisymmetric, quasi-static stress analyses were performed on two new KE training projectile designs. The first analysis indicated that structural failure was possible in the aft portion of the projectile due to compressive loading by the gun gases. Structural failure in this case would be circumferential yielding of the hollow flight body. The aft portion of the round was redesigned, and subsequent stress analysis showed the possibility of structural failure to be resolved. The finite-element modeling approach, the applied boundary conditions, and the results of the stress analyses conducted, based on use of the von Mises failure criterion, will be discussed in detail.

Elasto-Plastic Behavior of Thermoplastic Matrix Roller Chain Link Plates Reinforced With Steel Fibers

2000 ◽  
Author(s):  
Nurettin Arslan ◽  
Erol Sancaktar ◽  
Mehmet Celik
Keyword(s):  
Finite Element ◽  
Residual Stresses ◽  
Computer Program ◽  
Stress Analysis ◽  
Steel Fibers ◽  
Finite Elements Analysis ◽  
Roller Chain ◽  
Thermoplastic Matrix ◽  
Chain Link ◽  
Plastic Stress

Abstract The elastic and elasto-plastic stress analysis of thermoplastic matrix roller chain link plates reinforced with steel fibers is performed by using Finite Elements Analysis (FEA). A two-dimensional finite element computer program is developed for elasto-plastic stress analysis. Isoparametric quadratic element with four nodes is used with Lagrange polynomial as an interpolation function. The results of elastic and elasto-plastic finite element stress analysis by using the computer program prepared, are compared with experimental, (photoelastic) results. The spreads of the plastic zones due to the external load applied on the pin-hole of the plate and variations of the residual stresses are determined in different orientation angles and loads. It is shown that the geometry of the link plates can be designed to decrease the stress concentrations. Furthermore, it is shown that the tensile load limit of the roller chain link plate is extended by the residual stresses.

Advanced Structural Integrity Assessment Tools for Safe Long Term Operation: ATLAS+ Project — Status of the Activities of the WP3 on Modelling

2019 ◽  
Author(s):  
Stéphane Marie ◽  
Arnaud Blouin ◽  
Tomas Nicak ◽  
Dominique Moinereau ◽  
Anna Dahl ◽  
...  
Keyword(s):  
Large Scale ◽  
Structural Integrity ◽  
Assessment Tools ◽  
Local Approach ◽  
Coupled Models ◽  
Large Defect ◽  
Ductile Tearing ◽  
Term Operation ◽  
Integrity Assessment

Abstract The main objective and mission of the ATLAS+ project is to develop advanced structural assessment tools to address the remaining technology gaps for the safe and long term operation of nuclear reactor pressure coolant boundary systems. ATLAS+ WP3 focuses mainly on ductile tearing prediction for large defect in components: Several approaches have been developed to accurately model the ductile tearing process and to take into account phenomena such as the triaxiality effect, or the ability to predict large tearing in industrial components. These advanced models include local approach coupled models or advanced energetic approaches. Unfortunately, the application of these tools is today rather limited to R&D expertise. However, because of the continuous progress in the performance of the calculation tools and accumulated knowledge, in particular by members of ATLAS+, these models can now be considered as relevant for application in the context of engineering assessments. WP3 will therefore: • Illustrate the implementation of these models for industrial applications through the interpretation of large scale mock-ups (with cracks in weld joints for some of them), • Make recommendations for the implementation of the advanced models in engineering assessments, • Correct data from the conventional engineering approach by developing a methodology to produce J-Δa curve suitable case by case, based on local approach models, • Improve the tools, guidance and procedures for undertaking leak-before-break (LBB) assessments of piping components, particularly in relation to representing structural representative fracture toughness J-Resistance curves and the influence of weld residual stresses. To achieve these goals, WP3 is divided into 4 sub-WPs and this paper presents the progress of the work performed in each sub-WP after 24 months of activities.

scholarly journals Finite element modeling of geothermal source of heat pump in long-term operation

2020 ◽  
Vol 154 ◽  
pp. 04003
Author(s):  
Elżbieta Hałaj
Keyword(s):  
Finite Element ◽  
Heat Source ◽  
Heat Pump ◽  
Heat Exchangers ◽  
Transport Model ◽  
Heat Pumps ◽  
Initial Temperature Distribution ◽  
Term Operation ◽  
Borehole Heat Exchangers

Heat pumps become more and more popular heat source. They can be an alternative choice for obsolete coal fired boilers which are emissive and not ecological. During heat pump installation designing process, especially for heat pumps with higher heating capacity (for example those suppling larger buildings), a simulation of heat balance of ground heat source must be provided. A 3D heat transport model and groundwater flow in the geothermal heat source for heat pump (GSHP) installation was developed in FEFLOW according to Finite Element Modelling Method. The model consists of 25 borehole heat exchangers, arranged with spacing recommended by heat pump branch guidelines. The model consists of both a homogeneous, non-layered domain and a layered domain, which reflected differences in thermal properties of the ground and hydrogeological factors. The initial temperature distribution in the ground was simulating according to conditions typical for Europe in steady state heat flow. Optimal mesh refinement for nodes around borehole heat exchangers were calculated according to Nillert method. The aim of this work is to present influence of geological, hydrogeological factors and borehole arrangement in the energy balance and long term sustainability of the ground source. The thermal changes in the subsurface have been determined for a long term operation (30 years of operation period). Some thermal energy storage applications have also been considered.

Stress Analysis of Arctic Thaw Settlement with Gas Pipeline using Finite Element Method

2014 ◽  
Vol 18 (5) ◽  
pp. 78-84
Author(s):  
Kyung Il Kim ◽  
Kyu Jung Yeom ◽  
Young-Pyo Kim ◽  
Woo Sik Kim ◽  
Kyu Hwan Oh
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Analysis ◽  
Gas Pipeline ◽  
Thaw Settlement ◽  
Element Method

Determination of the Residual Stress State of High-Pressure Nozzles During Diamond Smoothing

2020 ◽  
pp. 3-11
Author(s):  
S.A. Zaides ◽  
A.N. Mashukov
Keyword(s):  
Finite Element ◽  
High Pressure ◽  
Stress State ◽  
Residual Stresses ◽  
Element Model ◽  
Depth Of Penetration ◽  
Residual Stress State ◽  
Hardening Treatment ◽  
Cylindrical Parts ◽  
Smoothing Process

The paper presents the results of a study that examines modelling of the polishing and hardening treatment of axisymmetric cylindrical parts such as high-pressure fittings with metal seals on the pipe and the rod. A finite element model of the diamond smoothing process was developed, which allowed one to determine the stress state in the deformation zone depending on the feed rate, tool deflection angle, pressing force, and depth of penetration into the material of the part. The analysis of the modelling results helped to identify a range of optimal modes for diamond smoothing. By using finite element modelling in ANSYS Workbench Mechanical it was possible to test those smoothing modes that were difficult to test experimentally. The study identified the most significant factors that influenced the formation of the maximum values of residual stresses in the surface layer of gate assemblies of high-pressure valves. The maximum values of compressive residual stresses, the value of which did not exceed the yield strength of the material were determined.

High-Pressure Pipelines Repaired by Steel Sleeve and Epoxy Composition

2013 ◽  
Vol 486 ◽  
pp. 181-188 ◽  
Author(s):  
Pavol Novák ◽  
Milan Žmindák ◽  
Zoran Pelagić
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
High Pressure ◽  
Material Properties ◽  
Welded Joint ◽  
Experimental Measurements ◽  
Filling Material ◽  
Epoxy Composition ◽  
State Of Stress ◽  
Steel Sleeve

The aim of this paper is first to determine the state of stress of welded joint repaired by steel sleeve and epoxy composition. Experimental measurements are performed on samples to determine required material properties. The structural analysis by finite element method (FEM) is performed for a pressurized pipe with insufficiently welded root and installed cold sleeve. Simulated is the case of depressurized pipes that could cause a breach of cohesion between filling material and surface of pipe or sleeve with usage of cohesive finite elements. In the end the sleeve dimensions are optimized with respect to maximum integrity to the repaired sleeve.

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