Determination of the Collapse and Propagation Pressure of Ultra-Deepwater Pipelines

2003 ◽  
Author(s):  
Rita G. Toscano ◽  
Chris M. Timms ◽  
Eduardo N. Dvorkin ◽  
Duane D. DeGeer
Keyword(s):  
Finite Element ◽  
Test Data ◽  
External Pressure ◽  
Full Scale ◽  
Test Program ◽  
Element Analysis ◽  
Line Pipe ◽  
Scale Test ◽  
Analysis Models

In the design of ultra-deepwater steel pipelines, it is important to be able to determine the pipe behaviour while subjected to external pressure and bending. In many cases, the ultra-deepwater lay process, where these high loads exist, governs the structural design of the pipeline. Much work has been performed in this area, and it is generally recognized that there is a lack of test data on full-scale samples of line pipe from which analyses can be accurately benchmarked. This paper presents the results of a nil-scale test program and finite element analyses performed on seamless steel line pipe samples intended for ultra-deepwater applications. The work involved obtaining full-scale test data and further enhancing existing finite element analysis models to accurately predict the collapse and post-collapse response of ultra-deepwater pipelines. The work and results represent a continuing effort aimed at understanding the behaviour of pipes subjected to external pressure and bending, accounting for the numerous variables influencing pipeline collapse, and predicting collapse and post-collapse behaviour with increasing confidence. The test program was performed at C-FER Technologies (C-FER), Canada, with the analyses undertaken by the Center for Industrial Research (CINI), Argentina. The results of this work have demonstrated very good agreement between the finite element predictions and the laboratory observations. This allows increased confidence in using the finite element models to predict collapse and post-collapse behaviour of pipelines subject to external pressure and bending.

Analyses of Full-Scale Tank Car Shell Impact Tests

2007 ◽  
Author(s):  
Y. H. Tang ◽  
H. Yu ◽  
J. E. Gordon ◽  
M. Priante ◽  
D. Y. Jeong ◽  
...  
Keyword(s):  
Finite Element ◽  
Test Data ◽  
Three Dimensional ◽  
Full Scale ◽  
Collision Dynamics ◽  
Dynamics Modeling ◽  
Dynamics Model ◽  
Rigid Plastic ◽  
Element Analysis ◽  
Closed Form Solutions

This paper describes analyses of a railroad tank car impacted at its side by a ram car with a rigid punch. This generalized collision, referred to as a shell impact, is examined using nonlinear (i.e., elastic-plastic) finite element analysis (FEA) and three-dimensional (3-D) collision dynamics modeling. Moreover, the analysis results are compared to full-scale test data to validate the models. Commercial software packages are used to carry out the nonlinear FEA (ABAQUS and LS-DYNA) and the 3-D collision dynamics analysis (ADAMS). Model results from the two finite element codes are compared to verify the analysis methodology. Results from static, nonlinear FEA are compared to closed-form solutions based on rigid-plastic collapse for additional verification of the analysis. Results from dynamic, nonlinear FEA are compared to data obtained from full-scale tests to validate the analysis. The collision dynamics model is calibrated using test data. While the nonlinear FEA requires high computational times, the collision dynamics model calculates gross behavior of the colliding cars in times that are several orders of magnitude less than the FEA models.

Predictive Residual Ovality for Reel-Laid Pipelines in Deepwater

2015 ◽  
Author(s):  
T. Sriskandarajah ◽  
Venu Rao
Keyword(s):  
Finite Element ◽  
Limit State ◽  
Accurate Determination ◽  
Integrated Approach ◽  
External Pressure ◽  
Full Scale ◽  
Finite Element Analyses ◽  
Element Analysis ◽  
Laser Measurements ◽  
Numerical Finite Element

Accurate determination of residual ovality is an important parameter for a successful deployment of single pipeline and pipe-in-pipe in deep waters wherein the integrity of empty pipes during installation depends upon the collapse resistance under external hydrostatic pressure. The reel-lay process of installation during which pipeline undergoes multiple strain cycles due to spooling, reeling and straightening has a significant bearing on pipe ovalisation and hence accurate determination residual ovality at the end of straightening process is one of the key inputs. It is industry practice to use numerical finite element analysis techniques to predict residual ovality of pipelines as full scale testing is expensive and time consuming. In view of the importance of residual ovality on the pipeline integrity particularly for deepwater applications, an integrated approach of testing and finite element simulation have been used to identify the correct numerical model that predicts residual ovality accurately. This paper discusses the full scale tests performed which include material testing and bend tests performed to simulate spooling and straightening process and the pipeline deformations recorded using laser measurements at different cycles of bending process. The paper presents a brief summary of numerical finite element analyses performed to validate the test results and the effect of element types and material models used in the finite element analyses on the predictability of residual ovality. The material evolution models and their effect on the predictability of remaining ovality are discussed in the paper. Comparisons are made on the predictive residual ovality for reel lay process on single pipe and pipe-in-pipe. The effect of residual ovality on the pipeline integrity for the lateral buckling limit state under combined bending and external pressure are discussed in the paper.

Finite element modeling of hexagonal wire reinforced embankment on soft clay

2000 ◽  
Vol 37 (6) ◽  
pp. 1209-1226 ◽  
Author(s):  
D T Bergado ◽  
C Teerawattanasuk ◽  
S Youwai ◽  
P Voottipruex
Keyword(s):  
Finite Element ◽  
Full Scale ◽  
Soil Reinforcement ◽  
Wire Mesh ◽  
Direct Shear ◽  
Full Scale Test ◽  
Element Analysis ◽  
Consolidation Process ◽  
Scale Test ◽  
Test Embankment

A full-scale test embankment was constructed on soft Bangkok clay using hexagonal wire mesh as reinforcement. This paper attempts to simulate the behavior of the full-scale test embankment using the finite element program PLAXIS. The agreement between the finite element results and the field data is quite good. The important considerations for simulating the behavior of the reinforced wall embankment were the method of applying the embankment loading during the construction process, the variation of soil permeability during the consolidation process, and the selection of the appropriate model and properties at the interface between the soil and reinforcement. The increased reinforcement stiffness tends to increase the reinforcement tension and increase the embankment forward rotation. The reinforcement tensions increased with the compression of the underlying soft foundation. The appropriate interface properties between the backfill soil and the hexagonal wire mesh reinforcement corresponding to the interaction mechanism at working stress conditions were dominated by the direct shear mechanism. The direct shear interaction coefficient of 0.9 was used.Key words: soil reinforcement, hexagonal wire mesh, finite element analysis, field embankment.

Numerical Simulations of Full-Scale Corroded Pipe Tests With Combined Loading

1997 ◽  
Vol 119 (4) ◽  
pp. 457-466 ◽  
Author(s):  
S. Roy ◽  
S. Grigory ◽  
M. Smith ◽  
M. F. Kanninen ◽  
M. Anderson
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Full Scale ◽  
Combined Loading ◽  
Pipe Failure ◽  
Element Analysis ◽  
Line Pipe ◽  
Safety Margins ◽  
Failure Predictions ◽  
Three Dimensional Finite Element

The ANSI/ASME B31G guideline has been useful to pipeline operators in assessing the integrity of corroded line pipe. Because large safety margins have had to be incorporated, the guidelines can be excessively conservative, which in turn can force costly repairs and replacements that may not actually be necessary. On the other hand, because the current guidelines consider only pressure loading and neglect bending and axial compression, they could give nonconservative failure predictions when combined loading exists. Therefore, a study was initiated to develop a theoretically sound methodology for assessing the integrity of corroded line pipe subjected to combined loading. A key step in the successful application of this methodology is the development of a sophisticated three-dimensional finite element procedure that can accurately simulate full-scale pipe tests under conditions of combined loading. This paper describes thirteen full-scale failure tests on artificially corroded pipes subjected to simultaneous internal pressure, bending, and longitudinal compression and presents a detailed account of the finite element analysis procedure that was developed to simulate these tests numerically. Additional finite element analyses that were conducted to investigate the effect of key parameters on failure, and to expand the corroded pipe failure database, are also discussed.

A New Rupture Prediction Model for Corroded Pipelines Under Combined Loadings

1998 ◽  
Author(s):  
Wei Wang ◽  
Marina Q. Smith ◽  
Carl H. Popelar ◽  
James A. Maple
Keyword(s):  
Prediction Model ◽  
Thermal Loading ◽  
Axial Loading ◽  
Full Scale ◽  
Element Analysis ◽  
Strain Limit ◽  
Rupture Pressure ◽  
Scale Test ◽  
Full Scale Tests

It is commonly believed that bending and other secondary loading will reduce the rupture pressure of a corroded pipe. This paper shows through theory, full-scale tests and finite element analysis (FEA) that this need not be the case in the field where displacement controlled bending and axial loading are induced by differential settlement and axial constraint. Based on this result, a new strain-based rupture prediction model is developed for buried corroded pipes subjected to internal pressure, lateral bending, thermal loading and residual stress. The selection of an appropriate “bulging factor,” the determination of a biaxial strain limit and the treatment of the heat affected zone (HAZ) are also discussed in the paper. The predicted rupture pressures agree well with the full-scale test results.

Material Property Testing for Finite Element Modelling of Coatings

2014 ◽  
Author(s):  
Helen Boyd ◽  
Erwan Karjadi ◽  
Harm Demmink ◽  
Guido Ridolfi ◽  
Han Keijzers
Keyword(s):  
Finite Element ◽  
Material Property ◽  
Full Scale ◽  
Test Procedures ◽  
Coating Materials ◽  
Element Analysis ◽  
Line Pipe ◽  
Insulation Materials ◽  
Finger Printing ◽  
Materials Used

In 2012 and 2013 Heerema Marine Contractors (HMC) performed full installation testing (bend, roller, tensioner and friction clamp) on pipes with different types of coating ranging from three layer polypropylene to thick insulation coating. The material property data as supplied by the coaters and/or the material suppliers appeared to have insufficient details for HMC to develop a model for the coated pipes. In order to obtain the missing details, HMC undertook a program of material finger printing for all coating materials used in the recent full scale testing in order to establish our own baseline for material properties. The reasons for doing so were; i) the data sheets from different suppliers of similar products were based on different test procedures and the results were not directly comparable, ii) initial testing indicated that the results quoted on the data sheets could not always be achieved by HMC and iii) the data as provided by the suppliers appeared to be not sufficient to be used for material models for finite element analysis. The focus to date has been on polyurethane based insulation materials, both for line pipe coating and for field joint coating, although the plan is to continue with polypropylene based insulation materials. The purpose of this paper is to discuss the setup of the full scale level winder and bend tests, the measurements and observations from the tests, the preliminary finite element analyses of the coating and the findings from the finger printing testing to date.

Collapse Performance of HTS (Helical Seam Two Step) Welded Line Pipe

2006 ◽  
Author(s):  
Franz Martin Knoop ◽  
Johannes Groß-Weege ◽  
Ulrich Marewski
Keyword(s):  
Finite Element Analysis ◽  
External Pressure ◽  
Future Research ◽  
Test Program ◽  
Element Analysis ◽  
Line Pipe ◽  
Research Issues ◽  
Various Boundary Conditions ◽  
Collapse Resistance ◽  
Pipe Manufacturing

Line pipe intended for offshore applications has to be designed predominantly with regard to external pressure in order to avoid collapse. High resistance to external pressure is vitally important for the use of pipes in such applications. A test program has been carried out in order to verify the resistance of HTS (helical seam two step) welded line pipe against collapse. It was demonstrated that the two step pipe manufacturing process has a beneficial effect on collapse resistance. HTS pipes therefore shows a good collapse performance compared to the design equations given in relevant offshore standards. One aim of the work carried out was to quantify the influence of relevant parameters on the result of full-scale collapse test by finite element analysis. The actual collapse pressures and those predicted using currently available design equations are compared and verified for various boundary conditions. The paper concludes with a discussion of the major findings and with a brief outlook to future research issues.

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