Reelability and Wall Thickness Optimization of HFI Pipeline Against the Sensitivity of Variation in Mismatch Parameters

2017 ◽  
Author(s):  
Dasharatha Achani ◽  
Vladimir Andreev
Keyword(s):  
Wall Thickness ◽  
Steel Strip ◽  
Compressive Strain ◽  
Local Buckling ◽  
Thickness Optimization ◽  
Cold Forming ◽  
Typical Design ◽  
Longitudinal Seam ◽  
Pipe Joint

High frequency Induction welded (HFW/HFI) linepipe is produced by cold forming from steel strip, bent into pipe and longitudinal seam welded. HFW/HFI linepipe has been attractive due to less expensive, improved lead time and tighter wall thickness tolerances and better control of mechanical properties compared to the seamless. Typical design drivers for wall thickness optimization of reeled pipeline are geometric and strength mismatch. HFI pipes gained the attention of reeling contactors because of tighter mismatch tolerances of geometry and strength. However, the limitation of wall thickness in producing the larger diameter pipes needs optimized wall thickness considering the sensitivity of the variation in mismatch properties and stress ratio. The present work is intended to check the capacity of the pipeline against the sensitivity of variation in mismatch parameters. A case study has performed for the reelability of 16” HFW pipe for a selected limiting wall thickness. The different cases of variation in mismatch parameters are considered for the sensitivity check. Finite element (FE) analyses using ABAQUS tool were performed to reel the sections of the pipe joint over the reel hub of the selected installation vessel. The model predictions for axial compressive strain are compared and discussed against the DNV local buckling criterion for displacement control.

Remaining Local Buckling Resistance of Corroded Pipelines

2010 ◽  
Author(s):  
Qishi Chen ◽  
Heng Aik Khoo ◽  
Roger Cheng ◽  
Joe Zhou
Keyword(s):  
Finite Element ◽  
Wall Thickness ◽  
Phase 1 ◽  
Compressive Strain ◽  
Research Work ◽  
Local Buckling ◽  
Model Verification ◽  
Metal Loss ◽  
General Corrosion ◽  
Buckling Resistance

This paper describes a multi-year PRCI research program that investigated the local buckling (or wrinkling) of onshore pipelines with metal-loss corrosion. The dependence of local buckling resistance on wall thickness suggests that metal-loss defects will considerably reduce such resistance. Due to the lack of experimental data, overly conservative assumptions such as a uniform wall thickness reduction over the entire pipe circumference based on the defect depth have been used in practice. The objective of this research work was to develop local buckling criteria for pipelines with corrosion defects. The work related to local buckling was carried out in three phases by C-FER and the University of Alberta. The first phase included a comprehensive finite element analysis to evaluate the influence of various corrosion defect features and to rank key parameters. Based on the outcome of Phase 1 work, a test matrix was developed and ten full-scale tests were carried out in Phase 2 to collect data for model verification. In Phase 3, over 150 parametric cases were analyzed using finite element models to develop assessment criteria for maximum moment and compressive strain limit. Each criterion includes a set of partial safety factors that were calibrated to meet target reliabilities selected based on recent research related to pipeline code development. The proposed criteria were applied to in-service pipeline examples with general corrosion features to estimate the remaining load-carrying capacity and to assess the conservatism of current practice.

Pipe Joint Management for Risers and Pipelines

2021 ◽  
Author(s):  
Ghiath (Guy) Mansour
Keyword(s):  
Fatigue Strength ◽  
Stress Concentration ◽  
Software Development ◽  
Wall Thickness ◽  
Stress Concentration Factor ◽  
Concentration Factor ◽  
Joint Management ◽  
Pipe Joints ◽  
Best Fit ◽  
Pipe Joint

Abstract Minimizing the stress concentration factor (SCF) in pipe joint welding subjected to fatigue is a major concern. Machining the joint ends is one way to achieve this. However, this adds cost, time, risk of potential crack starters, and loss of wall thickness which is detrimental for fatigue, strength, and engineering criticality assessment (ECA) in particular. Pipe joint sorting (certain joints in sequence) and end matching (rotating the pipe joints for best fit) are other ways. However, this adds time, costly logistics, risk of errors, and does not guarantee the minimum possible SCF is achieved. In a typical project, more pipe joints are procured than required in order to mitigate contingencies. For pipelines, this overage is typically a percentage of the required number of joints or pipeline length. For risers, typically double the required number of joints is procured where half of the joints is sent offshore for installation and the remaining half is kept onshore for a spare riser. Then, it becomes very important to send for installation the best pipe joints that produce the best (lowest) SCFs out of the entire batch of pipe joints. This requires calculating the SCF for every potential match of any random joints to be welded together, and then choosing the best joints. Performing such calculations by spreadsheet is not feasible considering the tremendous number of required iterations and calculations. A pipe joint management software development is presented herein which accomplishes this task and examples provided to illustrate the benefits. Note: Selecting pipe joints with the best end measurements, whether ID, OD, OOR, or thickness does not guarantee that the minimum possible SCFs will be achieved since the SCF is a function of all those measurements.

Local Buckling in end Expansion of Subsea Pipelines

2014 ◽  
Vol 69 (7) ◽  
Author(s):  
Jaswar Koto ◽  
Abd. Khair Junaidi ◽  
M. H. Hashim
Keyword(s):  
Crude Oil ◽  
Axial Force ◽  
Oil And Gas ◽  
Local Buckling ◽  
Offshore Platform ◽  
Offshore Pipeline ◽  
Specific Rule ◽  
Subsea Pipelines ◽  
Study Development

Offshore pipeline is mainly to transport crude oil and gas from offshore to onshore. It is also used to transport crude oil and gas from well to offshore platform and from platform to another platform. The crude oil and gas horizontally flows on the seabed, and then vertically flows inside the riser to the offshore platform. One of current issues of the oil and gas transportation system is an end expansion caused by the axial force. If the end expansion occurs over it limit can cause overstress to riser. This paper explores the effect of axial force toward local buckling in end expansion. In the study, development of programming in visual basic 2010 firstly was constructed using empirical equation. The programming code, then, was validated by comparing simulation result with actual data from company. As case study, the end expansion for various thicknesses of pipes was simulated. In this programming, DNV regulation is included for checking either design complied or not with regulation. However, DNV regulation doesn’t have specific rule regarding the end expansion but it is evaluated under load displacement control under strain condition.

scholarly journals Structural Assessment of the Hull Response of an FPSO Unit to Dropped Objects: A Case Study

2019 ◽  
Vol 26 (4) ◽  
pp. 39-46 ◽  
Author(s):  
Ozgur Ozguc
Keyword(s):  
Structural Damage ◽  
Local Buckling ◽  
Structural Response ◽  
Offshore Structures ◽  
Mechanical Equipment ◽  
Structural Members ◽  
Impact Area ◽  
Explicit Dynamic ◽  
The Impact

Abstract Offshore structures are exposed to the risk of damage caused by various types of extreme and accidental events, such as fire, explosion, collision, and dropped objects. These events cause structural damage in the impact area, including yielding of materials, local buckling, and in some cases local failure and penetration. The structural response of an FPSO hull subjected to events involving dropped objects is investigated in this study, and non-linear finite element analyses are carried out using an explicit dynamic code written LS-DYNA software. The scenarios involving dropped objects are based on the impact from the fall of a container and rigid mechanical equipment. Impact analyses of the dropped objects demonstrated that even though some structural members were permanently deformed by drop loads, no failure took place in accordance with the plastic strain criteria, as per NORSOK standards. The findings and insights derived from the present study may be informative in the safe design of floating offshore structures.

scholarly journals Axial and Radial Material Flow Analysis in Infeed Rotary Swaging of Tubes

2018 ◽  
Vol 190 ◽  
pp. 04003 ◽  
Author(s):  
Yang Liu ◽  
Marius Herrmann ◽  
Christian Schenck ◽  
Bernd Kuhfuss
Keyword(s):  
Wall Thickness ◽  
Material Flow ◽  
Flow Direction ◽  
Flow Analysis ◽  
Material Flow Analysis ◽  
Relative Wall Thickness ◽  
Cold Forming ◽  
Rotary Swaging ◽  
Fundamental Insight ◽  
Actual Ratio

In rotary swaging – an incremental cold forming production technique to reduce the diameter of axisymmetric parts – the material flow can be assumed to be predominantly axial and radial. The actual ratio of this axial and radial flow influences the mechanical properties and especially in tube forming the final geometry. It is known that during mandrel free infeed rotary swaging of tubes the wall thickness changes. The change is depending on the process parameters like incremental and cumulated strain. Hence, the ratio of axial and radial material flow changes. Consequently, the analysis of the wall thickness of rotary swaged tubes enables fundamental insight how to control the material flow direction. In this study, the infeed rotary swaging process of steel tubes with different wall thicknesses from 3 mm to 7 mm and rods were investigated with FEM under two feeding velocities. The axial and radial material flow and the resulting geometry were studied by the relative wall thickness. It could be seen that the relative wall thickness was affected by the feeding velocity as well as the initial wall thickness. The findings of the simulation were validated by rotary swaging experiments.

Combining Speed Control Function and Wye Passage in a Long Subsea Gas Line: A Case Study

2014 ◽  
Author(s):  
Hubert Lindner ◽  
Hans van Remmerden ◽  
Amit Shamgar
Keyword(s):  
Wall Thickness ◽  
Control Function ◽  
Operating Conditions ◽  
Single Individual ◽  
Individual Parameter ◽  
Operational Conditions ◽  
Battery Lifetime ◽  
Pipeline Inspection ◽  
Real Challenge

Challenging conditions for pipeline inspection can be caused by several different parameters and conditions (length, diameter changes, installations and operating conditions). Very often the real challenge is resulting from a combination of these influencing parameters. For example, a very long pipeline becomes particularly critical for battery lifetime if the flow rate is low. Each single individual parameter does not necessarily constitute such challenge. Some basic examples and a particular combination of pipeline parameters and operational conditions are presented in this article. The crucial parameters of the regarded pipeline are: 36″, about 700 km length, high wall thickness, high pressure and flow rates and a subsea wye piece. Some of these requirements are already demanding for former inspection tools. But the complex interaction of the features increases the challenge for the tool design significantly. Particularly the combination of high flow, high wall thickness and the wye piece passage required special attention. The article describes the pipeline properties and run conditions and the consequences for the entire cleaning and inspection program. Notably the interactions of the parameters regarding the MFL inspection are highlighted and the resulting tool concept is presented as well as the run results.

Machine Learning for Subsea Pipeline Reeling Mechanics

2020 ◽  
Author(s):  
Eric Giry ◽  
Vincent Cocault-Duverger ◽  
Martin Pauthenet ◽  
Laurent Chec
Keyword(s):  
Design Of Experiments ◽  
Wall Thickness ◽  
Large Diameter ◽  
Local Buckling ◽  
Statistical Regression ◽  
Element Analysis ◽  
Excessive Strain ◽  
Weld Area ◽  
Subsea Pipelines ◽  
Pipeline Design

Abstract Installation of subsea pipelines using reeling process is an attractive method. The pipeline is welded in long segments, typically several kilometers in length, and reeled onto a large diameter drum. The pipeline is then transported onto such reel to the offshore site where it is unreeled and lowered on the seabed. The deformation imposed on the pipeline while spooled onto the drum needs to be controlled so that local buckling is avoided. Mitigation of such failure is generally provided by proper pipeline design & reeling operation parameters. Buckling stems from excessive strain concentration near the circumferential weld area resulting from strength discontinuity at pipeline joints, mainly depending on steel wall thickness and yield strength. This requires the characterization of critical mismatches obtained by trial and error. Such method is a long process since each “trial” requires a complete Finite Element Analysis run. Such simulations are complex and lengthy. Occasionally, this can drive the selection of the pipeline minimum wall thickness, which is a key parameter for progressing the project. The timeframe of such method is therefore not compatible with such a key decision. The paper discusses the use of approximation models to capitalize on the data and alleviate the design cost. To do so, design of experiments and automation of the computational tool chain are implemented. It is demonstrated that initial complex chain of FEA computational process can be replaced using design space description and exploration techniques such as design of experiments combined with advanced statistical regression techniques in order to provide an approximation model. This paper presents the implementation of such methodology and the results are discussed.

Effect of Soil Restraint on the Buckling Response of Buried Pipelines

2010 ◽  
Author(s):  
Hiva Mahdavi ◽  
Shawn Kenny ◽  
Ryan Phillips ◽  
Radu Popescu
Keyword(s):  
Critical Strain ◽  
Mechanical Response ◽  
Ground Deformation ◽  
Compressive Strain ◽  
Local Buckling ◽  
Engineering Practice ◽  
Buried Pipelines ◽  
Limit States ◽  
Axial Thrust ◽  
New Criterion

Long-term large deformation geohazards can impose excessive deformation on a buried pipeline. The ground displacement field may initiate pipeline deformation mechanisms that exceed design acceptance criteria with respect to serviceability requirements or ultimate limit states. Conventional engineering practice to define the peak moment or compressive strain limits for buried pipelines has been based on the pipeline mechanical response for in-air conditions. This methodology may be conservative as it ignores the soil effect that imposes geotechnical loads and restraint on buried pipelines. The importance of pipeline/soil interaction and load transfer mechanisms that may affect local buckling of buried pipelines is not well understood. The authors previously developed a new criterion for local buckling strain of buried pipelines in stiff clay through response surface methodology (RSM) [1, 2]. In this paper the new criterion was compared with a number of available in-air based criteria to study the effect of soil restraint on local buckling response of buried pipelines. This criterion predicted larger critical strain than selected in-air based criteria which shows the significant influence of soil presence. The supportive soil effect is discussed. The soil restraining effect increases the pipeline bending resistance, when the pipeline is subjected to large displacement-controlled ground deformation. A correlation between Palmer’s et al. (1990) conclusion [3] and current study’s results has been made. The critical strain increases as the ratio between axial thrust and pipeline bending stiffness decreases.

The Initial Post-buckling Behavior of Face-Sheet Delaminations in Sandwich Composites

2003 ◽  
Vol 70 (2) ◽  
pp. 191-199 ◽  
Author(s):  
G. A. Kardomateas ◽  
H. Huang
Keyword(s):  
Interface Crack ◽  
Transverse Shear ◽  
Compressive Strain ◽  
Sandwich Beam ◽  
Local Buckling ◽  
Face Sheet ◽  
Material System ◽  
Buckling Behavior ◽  
Post Buckling ◽  
Composite Face

Should an interface crack between the layers of the composite face-sheet or between the core and the composite face-sheet of a sandwich beam/plate exists, local buckling and possible subsequent growth of this interface crack (delamination) may occur under compression. In this study, the buckling, and initial post-buckling behavior is studied through a perturbation procedure that is based on the nonlinear beam equations with transverse shear included. Closed-form solutions for the load and midpoint delamination deflection versus applied compressive strain during the initial postbuckling phase are derived. Illustrative results are presented for several sandwich construction configurations, in particular with regard to the effect of material system and transverse shear.

The Compilation and Study of Design Case for Railway Passenger Car

2013 ◽  
Vol 779-780 ◽  
pp. 506-509
Author(s):  
Yan Shuang Feng ◽  
Dong Jing ◽  
Song Wei ◽  
Kan Liang ◽  
Xin Yue Shi
Keyword(s):  
Design Problem ◽  
Technical Management ◽  
Future Design ◽  
Urgent Task ◽  
Management Method ◽  
Design Case ◽  
Railway Passenger ◽  
Design Case Study ◽  
Typical Design

To establish a learning and communication platform of design problem and solutions among designers for eliminating repetitive design errors become an important and urgent task. The analysis report on typical design case is a technical management method, which is a reliable and effective way to solve the problem mentioned above. This article expounds the implementation of the analysis report on typical design case and makes the suggestion on future design case study.

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