The Experts below are selected from a list of 1497 Experts worldwide ranked by ideXlab platform
Stelios Kyriakides - One of the best experts on this subject based on the ideXlab platform.
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liner wrinkling and collapse of bi material Pipe under axial compression
International Journal of Solids and Structures, 2015Co-Authors: Lin Yuan, Stelios KyriakidesAbstract:Abstract Lined Pipe describes a product where a carbon steel Pipe is lined internally with a thin layer of a corrosion resistant material in order to protect it from corrosive constituents in the hydrocarbons it carries. Most commonly the liner is brought into contact with the Carrier Pipe by mechanical expansion. Full-scale tests on this product have demonstrated that, under mechanical loads that plastically deform the composite structure, the thin liner can buckle and collapse inside an intact outer Pipe making the structure unserviceable. This paper investigates the extent to which typical lined Pipes can be axially compressed before liner collapse. Demonstration experiments on model lined systems illustrate that the liner, although supported by contact with the outer Pipe, first buckles unilaterally into an axisymmetric wrinkling mode at a relatively low strain. The wrinkles grow stably with compression but yield to a non-axisymmetric diamond-type mode that results in the collapse of the liner at a higher strain. This process has been modeled numerically starting with simulation of the mechanical expansion through which the composite structure is manufactured. The sensitivity of the collapse strain to the various parameters of the problem is studied and amongst other findings it is shown to be very sensitive to small geometric imperfections in the liner. It is also demonstrated that even modest amounts of internal pressure can delay liner collapse up to strains at which the outer Pipe collapses.
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liner wrinkling and collapse of girth welded bi material Pipe under bending
Applied Ocean Research, 2015Co-Authors: Lin Yuan, Stelios KyriakidesAbstract:Abstract Pipelines and flowlines that carry corrosive hydrocarbons are often protected by lining them internally with a thin layer of a corrosion resistant material. In the most economic method, the liner is brought in contact with a carbon steel Carrier Pipe by mechanical expansion. In applications involving severe plastic bending, such as winding onto a large diameter drum as is done in the reeling installation method, such a liner can wrinkle and collapse while the Carrier Pipe remains intact. Collapse has been shown to be sensitive to small initial geometric imperfections in the liner. A numerical framework for establishing the extent to which lined Pipe can be bent before liner collapse was presented in [14] , [15] , [16] . This framework, suitably extended is used here to examine the effect of girth welds on liner collapse. The modeling starts by simulating the expansion process that plastically deforms the two tubes bringing them into contact. Bending plastically the composite structure leads to differential ovalization of the two tubes and detachment of the liner. The girth weld locally prevents this detachment creating a periodic boundary disturbance in the liner. With increasing bending the periodic disturbance grows and eventually yields to buckling into a shell-type diamond-shaped mode that causes the liner to collapse inside the intact outer Pipe. The problem is investigated using a 12-inch Carrier Pipe base case. Comparing the collapse curvature of a girth-welded liner with imperfect liners free of welds that have the same collapse curvature, it is concluded that girth welds constitute a “weak” spot on the line. Results from a parametric study of factors that influence the collapse of a girth-welded are presented followed by recommendations.
Lin Yuan - One of the best experts on this subject based on the ideXlab platform.
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liner wrinkling and collapse of bi material Pipe under axial compression
International Journal of Solids and Structures, 2015Co-Authors: Lin Yuan, Stelios KyriakidesAbstract:Abstract Lined Pipe describes a product where a carbon steel Pipe is lined internally with a thin layer of a corrosion resistant material in order to protect it from corrosive constituents in the hydrocarbons it carries. Most commonly the liner is brought into contact with the Carrier Pipe by mechanical expansion. Full-scale tests on this product have demonstrated that, under mechanical loads that plastically deform the composite structure, the thin liner can buckle and collapse inside an intact outer Pipe making the structure unserviceable. This paper investigates the extent to which typical lined Pipes can be axially compressed before liner collapse. Demonstration experiments on model lined systems illustrate that the liner, although supported by contact with the outer Pipe, first buckles unilaterally into an axisymmetric wrinkling mode at a relatively low strain. The wrinkles grow stably with compression but yield to a non-axisymmetric diamond-type mode that results in the collapse of the liner at a higher strain. This process has been modeled numerically starting with simulation of the mechanical expansion through which the composite structure is manufactured. The sensitivity of the collapse strain to the various parameters of the problem is studied and amongst other findings it is shown to be very sensitive to small geometric imperfections in the liner. It is also demonstrated that even modest amounts of internal pressure can delay liner collapse up to strains at which the outer Pipe collapses.
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liner wrinkling and collapse of girth welded bi material Pipe under bending
Applied Ocean Research, 2015Co-Authors: Lin Yuan, Stelios KyriakidesAbstract:Abstract Pipelines and flowlines that carry corrosive hydrocarbons are often protected by lining them internally with a thin layer of a corrosion resistant material. In the most economic method, the liner is brought in contact with a carbon steel Carrier Pipe by mechanical expansion. In applications involving severe plastic bending, such as winding onto a large diameter drum as is done in the reeling installation method, such a liner can wrinkle and collapse while the Carrier Pipe remains intact. Collapse has been shown to be sensitive to small initial geometric imperfections in the liner. A numerical framework for establishing the extent to which lined Pipe can be bent before liner collapse was presented in [14] , [15] , [16] . This framework, suitably extended is used here to examine the effect of girth welds on liner collapse. The modeling starts by simulating the expansion process that plastically deforms the two tubes bringing them into contact. Bending plastically the composite structure leads to differential ovalization of the two tubes and detachment of the liner. The girth weld locally prevents this detachment creating a periodic boundary disturbance in the liner. With increasing bending the periodic disturbance grows and eventually yields to buckling into a shell-type diamond-shaped mode that causes the liner to collapse inside the intact outer Pipe. The problem is investigated using a 12-inch Carrier Pipe base case. Comparing the collapse curvature of a girth-welded liner with imperfect liners free of welds that have the same collapse curvature, it is concluded that girth welds constitute a “weak” spot on the line. Results from a parametric study of factors that influence the collapse of a girth-welded are presented followed by recommendations.
A. Nordquist - One of the best experts on this subject based on the ideXlab platform.
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Large-Scale Model Developed for Predicting the Carrier Pipe Potential Inside a Metallic Casing
Corrosion, 2013Co-Authors: F.m. Song, A. Nordquist, Pavan K. ShuklaAbstract:The corroding conditions of a cased Carrier Pipe segment are difficult to measure in the field. It is hard to know whether or how well the cased Pipe segment is cathodically protected. The Pipeline industry needs a tool that can predict the in situ corrosion potential of the Carrier Pipe in the casing annulus to determine the level of cathodic protection (CP). This work reports on a large-scale, three-dimensional computer model developed to make such a prediction. The casing wall may be treated as bare or coated on both or either of the external and internal surfaces. The Carrier Pipe is coated, and the coating quality inside the annulus may or may not be the same as the outside of the casing segment. The casing annulus is full of electrolytes or completely dry. The model is used to investigate the effect of several factors on the level of CP imposed on the Carrier Pipe in the annulus, including the coating quality on the Carrier Pipe, the casing wall native potentials (both external and internal), the pr...
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A Large-Scale Model Developed for Predicting the Corroding Conditions of a Carrier Pipe in a Casing
Volume 2: Pipeline Integrity Management, 2012Co-Authors: Fengmei Song, A. NordquistAbstract:The corroding conditions of a cased Carrier Pipe segment are difficult to measure in the field. It is hard to know whether or how well the cased Pipe segment is cathodically protected. The Pipeline industry needs a tool that can predict the in-situ corrosion potential of the Carrier Pipe in the casing annulus in order to determine the level of cathodic protection (CP). This work reports on a large-scale, three-dimensional computer model developed to make such a prediction. The casing wall may be treated as bare or coated on both or either of the external and internal surfaces. The Carrier Pipe is coated, and the coating quality inside the annulus may or may not be the same as the outside of the casing segment. The casing annulus is full of electrolytes. The model is used to investigate the effect of several factors on the level of CP imposed on the Carrier Pipe in the annulus, including the coating quality on the Carrier Pipe, the casing wall native potentials (both external and internal), the presence of a coating on a casing wall surface, and a metallic contact (between the casing and the Carrier Pipe) with the contact resistance being a variable. The effect of the voltage variation inside the Pipe metal wall is also investigated.Copyright © 2012 by ASME
Pavan K. Shukla - One of the best experts on this subject based on the ideXlab platform.
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Large-Scale Model Developed for Predicting the Carrier Pipe Potential Inside a Metallic Casing
Corrosion, 2013Co-Authors: F.m. Song, A. Nordquist, Pavan K. ShuklaAbstract:The corroding conditions of a cased Carrier Pipe segment are difficult to measure in the field. It is hard to know whether or how well the cased Pipe segment is cathodically protected. The Pipeline industry needs a tool that can predict the in situ corrosion potential of the Carrier Pipe in the casing annulus to determine the level of cathodic protection (CP). This work reports on a large-scale, three-dimensional computer model developed to make such a prediction. The casing wall may be treated as bare or coated on both or either of the external and internal surfaces. The Carrier Pipe is coated, and the coating quality inside the annulus may or may not be the same as the outside of the casing segment. The casing annulus is full of electrolytes or completely dry. The model is used to investigate the effect of several factors on the level of CP imposed on the Carrier Pipe in the annulus, including the coating quality on the Carrier Pipe, the casing wall native potentials (both external and internal), the pr...
D.l. Garrett - One of the best experts on this subject based on the ideXlab platform.
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The lifetime dynamics of a deep water riser design
Applied Ocean Research, 1998Co-Authors: A.j. Watters, I C Smith, D.l. GarrettAbstract:Abstract This paper discusses the dynamics of a hybrid production riser designed for a water depth of 1500 m in the harsh environment west of Shetland where one of the main design drivers is offshore installation time. To minimise installation time, a free standing riser was developed comprising a Carrier Pipe, top and bottom taper sections and an integral subsurface buoy connected by flexibles to the moored FPSO. The paper discusses the different dynamic characteristics of the structure during tow out, upending, connection and when installed. The simulation methods used, the design drivers, design compromises and parameter sensitivities are also discussed. It is concluded from extensive dynamic analysis and structural design that the proposed design is feasible and the estimated on-site installation time is 2–3 weeks.