Strength and Deformation Capacity of Corroded Pipes: The Joint Industry Project

2013 ◽  
Author(s):  
Erik Levold ◽  
Andrea Restelli ◽  
Lorenzo Marchionni ◽  
Caterina Molinari ◽  
Luigino Vitali
Keyword(s):  
Failure Modes ◽  
State Of The Art ◽  
Local Buckling ◽  
Bending Moment ◽  
External Pressure ◽  
Fe Model ◽  
Deformation Capacity ◽  
Offshore Pipelines ◽  
Strength And Deformation ◽  
Bending Loading

Considering the future development for offshore pipelines, moving towards difficult operating condition and deep/ultra-deep water applications, there is the need to understand the failure mechanisms and better quantify the strength and deformation capacity of corroded pipelines considering the relevant failure modes (collapse, local buckling under internal and external pressure, fracture / plastic collapse etc.). A Joint Industry Project sponsored by ENI E&P and Statoil has been launched with the objective to quantify and assess the strength and deformation capacity of corroded pipes in presence of internal overpressure and axial/bending loading. In this paper: • The State-of-the-Art on strength and deformation capacity of corroded pipes is presented; • The full-scale laboratory tests on corroded pipes under bending moment dominated load conditions, performed at C-FER facilities, are shown together with the calibrated ABAQUS FE Model; • The results of the ABAQUS FEM parametric study are presented.

Pipe Strength and Deformation Capacity: A Novel FE Tool for the Numerical Lab

2014 ◽  
Author(s):  
Lorenzo Maria Bartolini ◽  
Alberto Battistini ◽  
Lorenzo Marchionni ◽  
Antonio Parrella ◽  
Maurizio Spinazzè ◽  
...  
Keyword(s):  
Deep Water ◽  
Fem Analysis ◽  
Fe Model ◽  
Deformation Capacity ◽  
Mechanical Behaviors ◽  
Offshore Pipelines ◽  
Local Characteristics ◽  
Strength And Deformation ◽  
Global And Local ◽  
Buckle Arrestors

Future offshore pipelines development moves towards challenging operating condition and deep/ultra-deep water applications. Understanding the failure mechanisms and quantifying the strength and deformation capacity of pipelines, special components (buckle arrestors, wye, etc.) and in-line structures (in-line sled, in-line valve, in-line tee, etc.) is a need, under installation and operation loads, taking in account different geometrical characteristics and mechanical behaviors. The objective of this paper is to present and discuss recent FEM approaches integrating global and local analyses to evaluate the pipeline response and local effects, respectively. Thanks to this method the results coming from the global FEM analysis (main loads and driving phenomena) are used as input data for local FE Model with the aim to detect stress/strain intensification and other issues due to the local characteristics. In this paper: • The challenges of future deep water offshore pipelines are briefly presented; • The typical loading scenarios for pipelines during installation and operation are discussed; • The PipeONE 2014 tool, developed to facilitate the input/output data sharing between global and local FEM analyses, is presented and fully described in its main characteristics and capabilities; • An example is presented with the aim to understand and to appreciate the PipeONE 2014 functionality in FE modeling.

Submarine Pipeline Installation JIP: Strength and Deformation Capacity of Pipes Passing Over the S-Lay Vessel Stinger

2006 ◽  
Author(s):  
Enrico Torselletti ◽  
Luigino Vitali ◽  
Erik Levold ◽  
Kim J. Mo̸rk
Keyword(s):  
Water Depth ◽  
Failure Modes ◽  
Bending Moment ◽  
External Pressure ◽  
Submarine Pipeline ◽  
Design Guideline ◽  
Moment Capacity ◽  
Sea Bottom ◽  
Major Vessel ◽  
Gas Fields

The development of deep water gas fields using trunklines to carry the gas to the markets is sometime limited by the feasibility/economics of the construction phase. In particular there is a market for using S-lay vessels in water depth larger than 1000m. The S-lay feasibility depends on the applicable tension at the tensioner which is a function of water depth, stinger length and stinger curvature (for given stinger length by its curvature). This means that, without major vessel up-grading and to avoid too long stingers that are prone to damages caused by environmental loads, the application of larger stinger curvatures than presently allowed by current regulations/state of the art is needed. The work presented in this paper is a result of the project “Development of a Design Guideline for Submarine Pipeline Installation” sponsored by STATOIL and HYDRO. The technical activities are performed in co-operation by DNV, STATOIL and SNAMPROGETTI. The scope of the project is to produce a LRFD (Load Resistant Factor Design) design guideline to be used in the definition and application of design criteria for the laying phase e.g. to S and J-lay methods/equipment. The guideline covers D/t from 15 to 45 and applied strains over the overbend in excess of 0.5%. This paper addresses the failure modes relevant for combined high curvatures/strains, axial, external pressure and local forces due to roller over the stinger of an S-lay vessel and to sea bottom contacts, particularly: • Residual pipe ovality after laying, • Maximum strain and bending moment capacity. Analytical equations are proposed in accordance with DNV OS F101 philosophy and design format.

scholarly journals Test and Numerical Study on Monotonic Behavior of Complex CFT Column Joints

2019 ◽  
Vol 2019 ◽  
pp. 1-20
Author(s):  
Zeliang Yu ◽  
Bin Yang ◽  
Bin Jia ◽  
Yuhong Yan ◽  
Shaowen Xiao ◽  
...  
Keyword(s):  
Failure Modes ◽  
Numerical Study ◽  
Local Buckling ◽  
Steel Tube ◽  
Load Test ◽  
Fe Model ◽  
Beam Design ◽  
Overlap Joint ◽  
Cft Column ◽  
Steel Trusses

This paper presents a test and numerical investigation into the monotonic behavior of three different complex steel trusses to concrete-filled tubular (CFT) column joints. Based on an engineering structure, 1 : 4 reduced-scale specimens are manufactured and the three-dimensional subassembly testing system is designed to apply the monotonic load. Test phenomena and load-stress curves show that all three types of joints have a considerable load-carrying capacity and joint rigidity. Finite element (FE) analysis is adopted, and the stress distribution shows good agreement with test data. Both test and FE results show that local buckling and yielding in the root region of steel truss are the main failure modes of test joints and the core area of the CFT column remains intact which are in accordance with the design conception of “strong column and weak beam.” Design conception of proposed overlap joint form is then investigated based on the FE model, and results show that the optimized overlap joint can effectively reduce the stress concentration in the adjacent steel tube and beam member when compared to the traditional N-type overlap joint. Finally, the influence of the outer diaphragm on the stiffness of joint is analyzed. By comparing the end-displacement of the beam member, conclusion can be obtained that the beam flange thickness is suggested to be chosen as the outer diaphragm thickness. The forms of three different proposed joints and their design conceptions can provide good guidance for designers and engineers.

Prediction and Qualification of Radial Birdcage and Lateral Buckling of Flexible Pipes in Deepwater Applications

2015 ◽  
Author(s):  
Linfa Zhu ◽  
Zhimin Tan ◽  
Victor Pinheiro Pupo Nogueira ◽  
Jian Liu ◽  
Judimar Clevelario
Keyword(s):  
Failure Modes ◽  
Local Buckling ◽  
External Pressure ◽  
Design Guidelines ◽  
Prediction Theory ◽  
Flexible Pipe ◽  
Lateral Buckling ◽  
Operation Conditions ◽  
Flexible Pipes ◽  
Compressive Loads

Increasing oil exploitation in deepwater regions is driving the R&D of flexible pipes which are subjected to high external pressure loads from the hydrostatic head during their installation and operation. One of the challenges of flexible pipe design for such applications is to overcome the local buckling failure modes of tensile armor layers due to the combination of high external pressure, compressive loads and pipe curvature. This paper presents the latest progress in local buckling behavior prediction theory and the qualification process of flexible pipes. First, the mechanisms of two types of buckling behaviors, radial birdcage buckling and lateral buckling, are described. For each failure mode, the analytical buckling prediction theory is presented and the driving parameters are discussed. As part of the qualification process, the ability to resist radial birdcage and lateral buckling must be demonstrated. Suitable test protocols are required to represent the installation and operation conditions for the intended applications by deep immersion performance (DIP) tests. Several flexible pipes were designed based on radial birdcage and lateral buckling prediction theory, and pipe samples were manufactured using industrial production facilities for DIP tests. The results clearly show that flexible pipes following current design guidelines are suitable for deepwater applications. An alternative in-air rig was developed to simulate the DIP tests in a controlled laboratory environment to further validate the model prediction as a continuous development.

Further Advances on Concrete Coating Impact on Pipeline Strength

2017 ◽  
Author(s):  
Alberto Battistini ◽  
Luca Catena ◽  
Adelina Mancini ◽  
Lorenzo Marchionni ◽  
Antonio Parrella ◽  
...  
Keyword(s):  
Mechanical Behavior ◽  
Damage Evolution ◽  
Bending Stiffness ◽  
The State ◽  
Fe Model ◽  
Deformation Capacity ◽  
Strain Concentration ◽  
Concrete Damage ◽  
Strength And Deformation ◽  
Concrete Coating

Concrete Weight Coating is used in offshore industry to provide for pipeline vertical and lateral stability against waves and currents and to guarantee protection against fishing activities. Reinforced concrete coating of adequate strength, especially in case of thick coatings for stringent in-place stability requirements, entails additional bending stiffness and consequently strain concentration at field joints, thus significantly affecting the state of stress and strain on the pipe steel during laying firstly, and then during operations. Attention of the offshore pipeline industry has been focused in the development of experimental and theoretical activities in a more scientific way, which aimed to satisfy the need of a better knowledge in this field. Both analytical and FEM solutions are available in the free literature and relevant standards to predict the contribution of concrete coating layer on global pipeline strength and deformation capacity and simplified threshold values for the concrete damage are provided, as well. Generally, for installation analysis purpose, a pipeline with equivalent mechanical behavior (bending moment-curvature relationship) and physical (weight) properties is used in installation and operation analyses. No assumptions are typically made on concrete damage evolution to evaluate the decay of pipe capacity beyond the elastic range. In this paper new advances in modelling the mechanical behavior of concrete coated joints are discussed. In particular an advanced ABAQUS finite element model is proposed to take into account the effect of concrete coating damage on the overall capacity. The following effects have been accounted: • Non-linear stress-strain relationship of the steel at large usage factors/curvatures on the strain concentration at the field joint. • Concrete coating damage evolution on global pipeline bending stiffness. In this paper: • The state-of-the-art about published materials, numerical studies and design approaches on concrete material modelling and concrete coated pipes is briefly presented; • A FEM based analysis methodology is drawn and proposed for the strength and deformation capacity assessment of a concrete coated pipe; • The FEM model is calibrated on available full scale tests; • The results of a project case study performed with ABAQUS FE Model are given.

scholarly journals Buckling analysis of thin-walled metal liner of cylindrical composite overwrapped pressure vessels with depressions after autofrettage processing

2021 ◽  
Vol 28 (1) ◽  
pp. 540-554
Author(s):  
Guo Zhang ◽  
Haiyang Zhu ◽  
Qi Wang ◽  
Xiaowen Zhang ◽  
Mingfa Ren ◽  
...  
Keyword(s):  
Pressure Vessel ◽  
Local Buckling ◽  
Bending Moment ◽  
High Strength ◽  
External Pressure ◽  
Pressure Vessels ◽  
Buckling Analysis ◽  
Straight Section ◽  
Metal Liner ◽  
Autofrettage Pressure

Abstract The cylindrical filament wound composite overwrapped pressure vessels (COPV) with metal liner has been widely used in spaceflight due to their high strength and low weight. After the autofrettage process, the plastic deformation of the metal liner is constrained by composite winding layers, which introduce depressions to the metal liner that causes local buckling. To predict the local buckling of the inner liner with depressions of the pressure vessel after the autofrettage process, a local buckling analysis method for the metal liner of COPV was developed in this article. The finite element method is used to calculate the overall stress distribution in the pressure vessel before and after the autofrettage process, and the influence of local depressions on the buckling is evaluated. The axial buckling of the pressure vessel under external pressure is analyzed. The control equation of the metal liner with depressions is developed, considering the changes in the pressure and the bending moment of the liner depressions and its vicinity during the loading and unloading process. Taking the cylindrical COPV (38 L) with aluminum alloy liner as an example, the effects of liner thickness, liner radius, the thickness-to-diameter ratio, autofrettage pressure, and the length of straight section on the autofrettage process are discussed. The results show that the thickness of the inner liner has the most significant influence on the buckling of the liner, followed by the length of the straight section and the radius of the inner liner, while the autofrettage pressure has the least influence.

Safety Level on Different Offshore Pipeline Design Criteria: A Comparison Between DNV-OS-F101 and API RP-1111 Codes

2016 ◽  
Author(s):  
Luis D’Angelo ◽  
Hans M. Thorsen ◽  
Olav Fyrileiv ◽  
Leif Collberg ◽  
Sonia Furtado
Keyword(s):  
Failure Modes ◽  
Oil And Gas ◽  
Local Buckling ◽  
Oil And Gas Industry ◽  
External Pressure ◽  
Design Criteria ◽  
Load Parameter ◽  
Safety Level ◽  
Wide Range ◽  
Pipeline Design

Submarine pipelines are more often than before required to operate in harsh environments, especially for systems deployed in ultra-deep water. In order to minimize the installation tension due to the hanged section, they are installed empty and therefore the external pressure is often the prime load parameter for the design. New discoveries and associated technical challenges have generated important research and development endeavors in a wide range of disciplines in order to improve efficiency and reliability, but also keeping the risks associated with the new scenarios within an acceptable range. Some aspects that can be mentioned include, for instance, steel line grade improvements and manufacturing innovations of pipe products; more powerful lay vessels and development of new pipeline installation methods; determination of the mechanical behavior and the expected failure modes of concern for deep and long pipelines under combined loads; and the improved different design criteria like the DNV-OS-F101 (1) and API RP-1111 (2) codes. The intention of this paper is to review and compare three different pipeline design criteria well established in the oil and gas industry. The pipeline wall thickness design for pipe pressure containment (bursting), local buckling (system collapse) and propagating buckling for DNV-OS-F101 (1) and API RP-1111 (2) are discussed as well as the parameters used, definitions, safety philosophy and code limitations. A pipeline example is used to illustrate and compare the results.

The Bionic Optimization and Analysis and Calculation of the Cast-Steel Joint with Three Branches

2014 ◽  
Vol 548-549 ◽  
pp. 1618-1622
Author(s):  
Zheng Hao Zhu ◽  
Wen Feng Du ◽  
Zhi Fei Sun ◽  
Li Ming Zhu
Keyword(s):  
Failure Modes ◽  
Cast Steel ◽  
Local Buckling ◽  
Bending Moment ◽  
Axial Direction ◽  
Calculation Methods ◽  
Steel Joint ◽  
Architectural Structures ◽  
Steel Joints ◽  
Cast Steel Joint

The tree-like structure is a branch of space bionic structures,belonging to the Bionic Architectural Structures. Cast-steel joints with branches are the keys to build the tree-like structures.They are used widely,and the most common joints in our projects are cast-steel joints with two、three and four branches. The cast-steel joints with two branches are planar,while the joints with three and four branches are spatial.Until now,the basic theoretical researches about the cast-steel joints with branches are also relatively scarce.This paper did researches about mechanical properties, calculation methods and structural optimization of the cast-steel joints with three branches deeply and systematically. The result shows that the bending moment has a big influence on the value of the max stress. And the three main failure modes of the cast-steel joint with three branches are yield of the main tubular along the axial direction, local buckling at the connection of the main tubular and branches, and the tearing out of the branches.

Bending Capacity of Pipe Bends in Deepwater Conditions

2010 ◽  
Author(s):  
Shulong Liu ◽  
Alastair Walker ◽  
Philip Cooper
Keyword(s):  
Internal Pressure ◽  
Induction Heating ◽  
Wall Thickness ◽  
Failure Modes ◽  
Limit State ◽  
Bending Moment ◽  
External Pressure ◽  
Fe Method ◽  
Moment Capacity ◽  
Operation Conditions

Offshore pipeline systems commonly incorporate induction-heating formed bends along flowlines and in pipeline end termination assemblies and spools. In deepwater locations, the pipeline and bends are subjected to various combinations of external pressure, internal pressure, bending moment and temperature changes, during installation, and operation. Although there is a history of research into the limiting loads and failure modes of such bends and pipelines systems there is, as yet, no comprehensive guidance to enable the calculation of the maximum capacity under combined bending and external pressure loading. Conservative guidance is presented in DNV OS-F101 (2007) [1] that proposes increasing the pipe wall thickness to reduce the effect of external pressure collapse effects thus enabling bending formulations relevant to straight pipe to be used. This proposed approach leads to unfeasibly large wall thickness requirements in very deepwater applications. There is therefore a requirement for a method to design deepwater bends for installation and operation conditions with levels of safety comparable with those used in the design of straight sections of pipelines that does not depend on the requirement to increase the wall thickness to the extent proposed in the current DNV guidance. In this study, a nonlinear FE method using ABAQUS is proposed to evaluate the ultimate capacities of induction-heating formed bends. The method takes into account the combined effects of non-linear material properties, initial ovality, wall thinning/thickening, external or internal pressure, internal CRA cladding and temperature change on the ultimate moment capacity of the bend. The numerical model is validated by comparison with available published results. The method developed here is based on the limit state design formulations in the current DNV OS-F101 guidance.

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