Leak Detection Assessment of a Through Wall Crack in a Circumferential Weld

2017 ◽  
Author(s):  
Peter Gill ◽  
Colin Madew ◽  
Steve Booth
Keyword(s):  
Finite Element ◽  
Thermal Field ◽  
Crack Opening ◽  
Leak Detection ◽  
Defect Size ◽  
Element Analysis ◽  
Thermal Fields ◽  
Start Up ◽  
Tensile Data ◽  
Fit For Purpose

A leak detection assessment at a circumferential weld has been carried out to support a Leak-before-Break argument. This was performed using detailed finite element analysis (FEA) of the component to determine limiting defect sizes and crack opening areas. Leak rates of CO2 were then calculated and were found to be at an acceptable level. The loading on the component were complex, including thermal, pressure and weld residual stresses. The thermal field originated from both a steady state operating condition and hold point during start up plant state. Computational Fluid Dynamics (CFD) was used to generate the thermal fields for this component and the crack was postulated to occur at the region of highest opening stress along the weld. In addition to the thermal field, the weld was also subjected to a residual stress, which was applied in the model via a novel application method that is described in the paper. The FEA incorporated temperature dependent Ramberg-Osgood stress strain data that was generated from tensile data. For the limiting defect size calculation, lower bound material properties were used, and for the crack opening area, mean properties were used. Various crack sizes were considered and J-integrals were calculated and compared against the material toughness of the weld. This enabled the calculation of a limiting defect size, and crack opening area, so that a leakage rate could then be calculated. Contour independence was observed for the J-integral evaluation giving confidence that the finite element meshes were fit for purpose.

Study on the Thermal Field Distribution of Steel Claws for Anode in Aluminium Electrolysis Cell

2015 ◽  
Vol 1120-1121 ◽  
pp. 1089-1092
Author(s):  
Qing Dong Qin
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Field Distribution ◽  
Thermal Field ◽  
Voltage Drop ◽  
The Other ◽  
Electrolysis Cell ◽  
Aluminium Electrolysis ◽  
Element Analysis ◽  
Anode Carbon

The electricity consuming of aluminium electrolysis cell is affected by the voltage drop of anode steel claws during the aluminium electrolysis course. The resistivity of anode steel claws is affected by the temperature. In the present study, the thermal field distribution of anode steel claws was studied by finite element analysis. The results show that the thermal energy of anode steel claws come from anode carbon blocks and environment. The temperature of steel claws less than 1/3 height is affected by anode carbon blocks, and the other part is affected by surrounding temperature. According the results, the principle of the new anode steel claw design is proposed.

On the Influence of the Corrosion Defect Size in the Welding Bead, Heat-Affected Zone, and Base Metal in Pipeline Failure Pressure Estimation: A Finite Element Analysis Study

2019 ◽  
Vol 141 (3) ◽  
Author(s):  
G. Terán ◽  
S. Capula-Colindres ◽  
J. C. Velázquez ◽  
D. Angeles-Herrera ◽  
E. Torres-Santillán
Keyword(s):  
Finite Element ◽  
Base Metal ◽  
Heat Affected Zone ◽  
Defect Size ◽  
Localized Corrosion ◽  
Defect Depth ◽  
Element Analysis ◽  
Failure Pressure ◽  
Corrosion Defect ◽  
Pipeline Failure

In this study, failure pressure prediction was conducted in a pipeline with localized corrosion in base metal (BM), heat-affected zone (HAZ), and welding bead (WB) by finite element (FE) analysis. In the gas pipeline industry, there are methods (B31G, RESTRENGH, Shell, DNV, PCORR, and Fitnet FFS) and authors' approaches (Choi and Cronin) to determine the failure pressure. However, one disadvantage of these methods is that their equations do not consider damage corrosion at the HAZ or WB. They consider corrosion only in the BM. The corrosion shape is rectangular with a radius at the edges. In this study, the corrosion defect depth (d) was varied. The corrosion defect length (L) and the corrosion defect width (W) were equal. A type of rectangular corrosion defect with a radius at the edges in the longitudinal and circumferential directions was proposed. True stress–strain curves for BM, HAZ, and WB of an API 5 L X52 were introduced in the FE program. The results show that the pressure decreases as d, L, and W increase. This is because the damage corrosion is more severe as it grows, which causes the failure pressure to decrease.

Development of Material Constants for Nonlinear Finite-Element Analysis

1988 ◽  
Vol 61 (5) ◽  
pp. 879-891 ◽  
Author(s):  
Robert H. Finney ◽  
Alok Kumar
Keyword(s):  
Experimental Data ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Large Strain ◽  
Strain Range ◽  
Nonlinear Finite Element ◽  
Element Analysis ◽  
Material Models ◽  
Tensile Data

Abstract The determination of the material coefficients for Ogden, Mooney-Rivlin, Peng, and Peng-Landel material models using simple ASTM D 412 tensile data is shown to be a manageable task. The application of the various material models are shown to be subject to the type and level of deformation expected, with Ogden showing the best correlation with experimental data over a large strain range for the three types of strain investigated. At low strains, all of the models showed reasonable correlation.

Nano-Hydroxyapatite Coatings on Titanium Substrates. Finite Element Analysis of Process and Experimental Plasma Thermal Sprayed Coatings

2007 ◽  
Vol 361-363 ◽  
pp. 745-748 ◽  
Author(s):  
Helene Citterio-Bigot ◽  
S. Jakani ◽  
Abdelilah Benmarouane ◽  
Pierre Millet ◽  
Alain Lodini
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Thermal Field ◽  
Thermal Spraying ◽  
Average Crystallite Size ◽  
Nucleation Site ◽  
Layer By Layer ◽  
Element Analysis ◽  
Hydroxyapatite Coatings ◽  
Crystallite Sizes

The aim of this study was to create a nano-structured coating using Plasma Thermal Spraying (PTS). This process consists in introducing pre-agglomerated nanosized particles in a high-temperature and high-velocity gas jet and projected them onto the substrate to form, layer by layer, a nanostructured coating. In order to retain nanometer grain sizes in the deposited coating through specific PTS technologies, a thermal field and velocity distribution in the plasma jet are analytically calculated. A finite element analysis is employed to calculate the thermal field evolution inside the agglomerated particles and the thermal induced internal stress distribution is determined. The parameters determined by the theoretical analysis are used for experimental coatings. The average crystallite size of nano-hydroxyapatite powder was 90nm. After deposit via Plasma Thermal Spraying (PTS) process and followed by a 2 hours heat treatment to reduce amorphous fraction, the experimental deposited coating shows that it retains the nanometer crystallite sizes. The substructure of nanocrystals was evaluated at about 120nm in size. Such a nanocoating may play the role of nucleation site to bone, allowing a faster stabilization of the implant.

The Prediction of Fatigue Crack Opening Behavior Using Cyclic Crack Tip Opening Displacement by Finite Element Analysis

2006 ◽  
Vol 324-325 ◽  
pp. 295-298 ◽  
Author(s):  
Hyeon Chang Choi
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fatigue Crack ◽  
Crack Opening ◽  
Crack Tip ◽  
Crack Tip Opening Displacement ◽  
Opening Displacement ◽  
Element Analysis ◽  
Element Size ◽  
Crack Tip Opening

An elastic-plastic finite element analysis (FEA) is performed to examine the opening behavior of fatigue crack, where the contact elements are used in the mesh of the crack tip area. The relationship between fatigue crack opening behavior and cyclic crack tip opening displacement was studied in the previous study. In this paper, we investigate the effect of the element size when predict fatigue crack opening behavior using the cyclic crack tip opening displacement obtained from FEA. The cyclic crack tip opening displacement is well related to fatigue crack opening behavior.

Application of Finite Element Analysis for the Prediction of the Fatigue Lifetime of Spot Welds with Triple SPCC plates

2007 ◽  
Vol 345-346 ◽  
pp. 1453-1456
Author(s):  
Byoung Ho Choi ◽  
Dong Ho Joo ◽  
Sam Hong Song
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Shell Model ◽  
Crack Opening ◽  
Equivalent Stress ◽  
Shear Loading ◽  
Opening Angle ◽  
Element Analysis ◽  
Fatigue Lifetime ◽  
Empirical Prediction

The fatigue characteristic of triple spot welded SPCC plates with the variation of the thickness and the geometry under tensile-shear loading is studied by finite element analysis (FEA) and the obtained data is compared with experimental data. Using 3-D solid element model and 3-D beam-shell model, the maximum equivalent stress and the beam deformation angle (BDA) for various thickness and geometry is studied. The linear relation between crack opening angle (COA) from experiment and the BDA from FEA for beam-shell model is represented, and the empirical prediction of fatigue lifetime is proposed using the relation between COA and BDA.

Study on Thermal Placement Optimization of Embedded MCM

2011 ◽  
Vol 189-193 ◽  
pp. 2269-2273
Author(s):  
Chun Yue Huang ◽  
Tian Ming Li ◽  
Ying Liang ◽  
He Geng Wei
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Temperature Field ◽  
Field Distribution ◽  
Temperature Difference ◽  
Optimization Algorithm ◽  
Thermal Field ◽  
Maximum Temperature ◽  
Element Analysis ◽  
Placement Optimization

In the thermal design of embedded multi-chip module (MCM), the placement of chips has a significant effect on temperature field distributing, thus influences the reliability of the embedded MCM. The thermal placement optimization of chips in embedded MCM was studied in this paper, the goal of this work is to decrease temperature and achieve uniform thermal field distribution within embedded MCM. By using ANSYS the finite element analysis model of embedded MCM was developed, the temperature field distributing was calculated. Based on genetic algorithms, chips placement optimization algorithm of embedded MCM was proposed and the optimization chips placement of embedded MCM was achieved by corresponding optimization program. To demonstrate the effectiveness of the obtained optimization chips placement, finite element analysis (FEA) was carried out to assess the thermal field distribution of the optimization chips placement in embedded MCM by using ANSYS. The result shows that without chips placement optimizing the maximum temperature and temperature difference in embedded MCM model are 87.963°C and 2.189°C respectively, by using chips placement optimization algorithm the maximum temperature drop than the original 0.583°C and the temperature difference is only 0.694°C . It turns out that the chip placement optimization approach proposed in this work can be effective in providing thermal optimal design of chip placement in embedded MCM.

Upheaval Creep of Rock Dumped Flexible Flowline

2014 ◽  
Author(s):  
Yang Zhengmao ◽  
Kristian Norland ◽  
Neil Brown ◽  
Daniel Karunakaran
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Pressures ◽  
Elevated Temperatures ◽  
Water Injection ◽  
Analysis Model ◽  
Flexible Pipe ◽  
Element Analysis ◽  
Nonlinear Bending ◽  
Start Up

For the protection from dropped object/fishing trawl impact, flexible flowlines are normally trenched or rock-dumped. And hence, upheaval buckling and lateral buckling may be promoted by the elevated temperatures and high pressures. Due to the unique properties of un-bonded flexible flowline, the flexible flowline may creep in the trench or rock berm when it is subjected to cyclic pressure and temperature changes due to start-up and shut-down of flowline in service. In this paper, a finite element analysis model for the global buckling and upheaval creep of flexible flowline is proposed. In this model the effect of bending stiffness hysteresis are considered in addition to the temperature and pressure changes in each start-up/ shut-down cycle. A case study of a 10″ water injection flowline is performed by using finite element analysis software package ANSYS. The nonlinear general beam section is used to simulate the specific flexible pipe behavior, nonlinear bending behavior but linear axial behavior.

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