Assessment of the Complexity of Stress/Strain Conditions of X100 Steel Pipeline and the Effect on the Steel Corrosion and Failure Pressure Prediction

2012 ◽  
Author(s):  
Luyao Xu ◽  
Frank Y. Cheng
Keyword(s):  
Steel Corrosion ◽  
Local Stress ◽  
High Strength ◽  
Complex Stress ◽  
Fe Model ◽  
Operating Pressure ◽  
Stress Strain ◽  
Failure Pressure ◽  
Corrosion Defects ◽  
Pipeline Design

In this work, a finite element (FE) model was developed to simulate the complex stress/strain conditions potentially exerted on the northern pipelines due to the synergism of internal pressure, soil strain and local stress/strain concentration at corrosion defects. The effects of pre-strain on corrosion of the steel and the pipeline failure pressure were investigated. Results demonstrated that a high intensity stress/strain field generates preferentially at the bottom of corrosion defect. The increase of operating pressure would increase the stress concentration at defect and the plastically deformed area. Both tensile and compressive soil strains increase the stress intensity and plastic deformation. Thus, a pipe containing corrosion defects or mechanical dents is susceptible to hoop cracking or local bulking under the tensile and compressive soil strains, respectively. Moreover, while an elastic strain enhances slightly the steel corrosion, the effect of plastic strain is much remarkable. In optimal pipeline design, the reliable risk assessment of high-strength steel pipelines should consider the corrosion enhancement and defect propagation under the complex stress/strain conditions.

Assessment on failure pressure of high strength pipeline with corrosion defects

2013 ◽  
Vol 32 ◽  
pp. 209-219 ◽  
Author(s):  
Bin Ma ◽  
Jian Shuai ◽  
Dexu Liu ◽  
Kui Xu
Keyword(s):  
High Strength ◽  
Failure Pressure ◽  
Corrosion Defects

In-Field Application of Steel Strip Reinforcement for Pipeline External Rehabilitation

2010 ◽  
Author(s):  
Nicholas J. Venero ◽  
Tim J. M. Bond ◽  
Raymond N. Burke ◽  
David J. Miles
Keyword(s):  
Steel Strip ◽  
New Technology ◽  
High Strength ◽  
Field Application ◽  
Operating Conditions ◽  
Operating Pressure ◽  
Precise Control ◽  
Ultra High Strength Steel ◽  
Structural Adhesive ◽  
Pipeline Design

A new technology for external rehabilitation of pipelines, known as XHab™, has been developed. This method involves wrapping multiple layers of ultra-high strength steel (UHSS) strip in a helical form continuously over an extended length of pipeline using a dedicated forming and wrapping machine. The reinforcement afforded by the strip can be used to bring a defective section of pipe (e.g. externally corroded or dented) back to its original allowable operating conditions, or even to increase the allowable operating pressure if the desired operating conditions exceed the original pipeline design limits. This paper describes the design, manufacture and testing process for a self-propelled wrapping machine for in-field rehabilitation. The wrapping apparatus consists of several major components including an opening sufficiently wide to receive the pipe, a movement assembly, a winding head, a preforming device, an accumulator and an oscillating adhesive applicator. The wrapping apparatus uses the winding head to wrap the reinforcing steel strip around the pipe. The movement assembly uses a pair of tracks in contact with the pipe to drive the wrapping apparatus along which enables helical wrapping of the reinforcing strip material. The oscillating adhesive assembly applies structural adhesive to the pipe immediately before the strip is wound. The winding head, motive assembly and adhesive applicator are electronically synchronized to one another to enable precise control of pitch and adhesive volume. The paper also describes the field application of XHab including mobilization/demobilization of equipment and interaction with other rehabilitation equipment, as well as specific aspects such as initiation and termination of wrapping, protection of rehabilitated area and implementation of cathodic protection.

Testing and Analysis of Steel Strip Reinforcement for Pipeline External Rehabilitation

2010 ◽  
Author(s):  
David J. Miles ◽  
Tim J. M. Bond ◽  
Raymond N. Burke ◽  
Ruben van Schalkwijk
Keyword(s):  
Steel Strip ◽  
New Technology ◽  
High Strength ◽  
Full Scale ◽  
Operating Conditions ◽  
Operating Pressure ◽  
Batch Tests ◽  
Girth Welds ◽  
The Individual ◽  
Pipeline Design

A new technology for external rehabilitation of pipelines, known as XHab™, has been developed. This method involves wrapping multiple layers of ultra-high strength steel strip (UHSS) in a helical form continuously over an extended length of pipeline using a dedicated forming and wrapping machine. The reinforcement afforded by the strip can be used to bring a defective section of pipe (e.g. externally corroded or dented) back to its original allowable operating conditions, or even to increase the allowable operating pressure if the desired operating conditions exceed the original pipeline design limits. This paper describes the full scale burst testing and analysis of defective pipes which have been repaired using the XHab process. The full scale test sections are 30″ × 0.5″ API 5L X52 DSAW pipe and include the following specimens: • Bare pipe with no defects; • Bare pipe with single machined defect; • Wrapped pipe with single machined defect and designed reinforcement; • Wrapped pipe with single machined defect and insufficient reinforcement; • Wrapped pipe with interacting defect array and designed reinforcement. The above full scale burst tests are supplemented by FEA models using ABAQUS. The material models for the steel pipe, UHSS strip, defect patch material and strip adhesive are based on measured data from the batch tests and tuned against the control burst test results. The structural behavior in the individual metallic and non-metallic elements can therefore be examined more closely, particularly in the region of the defect and where the wrapped strip crosses seam and girth welds.

Design of Pipeline Damage for the BP X100 Operational Trial

2010 ◽  
Author(s):  
Robert M. Andrews ◽  
James Johnson ◽  
Julie Crossley
Keyword(s):  
Mechanical Damage ◽  
High Strength ◽  
Operating Pressure ◽  
Technology Program ◽  
Pressure Cycling ◽  
Defect Assessment ◽  
Ongoing Work ◽  
Current Assessment ◽  
Corrosion Defects ◽  
Girth Welds

As part of an ongoing pipeline technology program for BP Alaska, a 1 km, 48-inch diameter, X100 demonstration pipeline was constructed and operated for a period of two years. Artificial defects were introduced into one of the two test sections. These defects were intended to demonstrate that current assessment methods could be used to predict the behaviour of pipeline defects in a very high strength steel under realistic conditions including accelerated pressure cycling and a range of cathodic protection levels. The defects included in the trial were volumetric corrosion, mechanical damage, arc strikes and girth weld defects. The volumetric corrosion defects included both isolated defects and pairs of interacting defects. All the defects and details such as the girth welds were assessed for fatigue failure in addition to failure at the Maximum Operating Pressure. This paper describes the design of the defects for the trial. The defects were designed to be close to failure, so as to provide a realistic test of the predictive methods. Current methods were used including the Pipeline Defect Assessment Manual (PDAM) and ongoing work sponsored by PRCI.

scholarly journals Safety assessment of corrosion-defective natural gas pipeline under ground overload based on FEM

2021 ◽  
Vol 37 (1) ◽  
Author(s):  
T, Zheng ◽  
Z. Liang ◽  
J. Zhang ◽  
S. Tang ◽  
X. Xiao
Keyword(s):  
Internal Pressure ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Local Stress ◽  
Von Mises Stress ◽  
Stress And Strain ◽  
Failure Pressure ◽  
Corrosion Defect ◽  
Corrosion Defects ◽  
Von Mises

Aiming at the safety problem of the pipeline containing corrosion defects caused by ground overload, a novel method is developed to assess the safety of buried pipelines with corrosion defects and predict the failure pressure. The effects of parameters including internal pressure, ground overload, length of the loading area, corrosion defect depth, buried depth and soil Young’s modulus, are discussed. Ground overload greatly increases the von Mises stress and strain at the corrosion defect location and decreases the internal pressure threshold. The von Mises stress and strain are an obvious nonlinear relationship with internal pressure. The high stress and strain area expand along the diagonal direction of the defect area. The local stress and strain concentration at the corrosion defect increases with the increase of ground overload, length of the loading area and corrosion defect depth, which reduces the failure pressure of the pipeline. Increasing the buried depth and soil Young’s modulus would effectively reduce local stress and strain concentration, and increase the failure pressure of the pipeline. The pipeline settlement displacement increases with the increase of internal pressure, ground overload, length of the loading area, and decreases with the increase of pipeline buried depth and soil Young’s modulus.

Effects of local stress, strain, and hydrogen content on hydrogen-related fracture behavior in low-carbon martensitic steel

2021 ◽  
pp. 116828
Author(s):  
Akinobu Shibata ◽  
Takashi Yonemura ◽  
Yuji Momotani ◽  
Myeong-heom Park ◽  
Shusaku Takagi ◽  
...  
Keyword(s):  
Hydrogen Content ◽  
Fracture Behavior ◽  
Martensitic Steel ◽  
Local Stress ◽  
Low Carbon ◽  
Stress Strain ◽  
Carbon Martensitic Steel

Numerical modeling of stress-strain relationships for advanced high strength steels

2021 ◽  
Vol 182 ◽  
pp. 106687
Author(s):  
Yu Xia ◽  
Chu Ding ◽  
Zhanjie Li ◽  
Benjamin W. Schafer ◽  
Hannah B. Blum
Keyword(s):  
Numerical Modeling ◽  
High Strength Steels ◽  
High Strength ◽  
Stress Strain ◽  
Advanced High Strength Steels

A modified physical model of high-strength water hydraulic artificial muscles considering the effects of geometry and material properties

2021 ◽  
pp. 095440622199907
Author(s):  
Zengmeng Zhang ◽  
Jinkai Che ◽  
Peipei Liu ◽  
Yunrui Jia ◽  
Yongjun Gong
Keyword(s):  
Physical Model ◽  
Relative Error ◽  
Wall Thickness ◽  
Material Properties ◽  
High Strength ◽  
Artificial Muscles ◽  
Operating Pressure ◽  
Rubber Tube ◽  
Contraction Ratio ◽  
Water Hydraulic

Compared with pneumatic artificial muscles (PAMs), water hydraulic artificial muscles (WHAMs) have the advantages of high force/weight ratio, high stiffness, rapid response speed, large operating pressure range, low working noise, etc. Although the physical models of PAMs have been widely studied, the model of WHAMs still need to be researched for the different structure parameters and work conditions between PAMs and WHAMs. Therefore, the geometry and the material properties need to be considered in models, including the wall thickness of rubber tube, the geometry of ends, the elastic force of rubber tube, the elongation of fibers, and the friction among fiber strands. WHAMs with different wall thickness and fiber materials were manufactured, and static characteristic experiments were performed when the actuator is static and fixed on both ends, which reflects the relationship between contraction force and pressure under the different contraction ratio. The deviations between theoretical values and experimental results were analyzed to investigate the effect of each physical factor on the modified physical model accuracy at different operating pressures. The results show the relative error of the modified physical model was 7.1% and the relative error of the ideal model was 17.4%. When contraction ratio is below 10% and operating pressure is 4 MPa, the wall thickness of rubber tube was the strongest factor on the accuracy of modified model. When the WHAM contraction ratio from 3% to 20%, the relative error between the modified physical model and the experimental data was within ±10%. Considering the various physical factors, the accuracy of the modified physical model of WHAM is improved, which lays a foundation of non-linear control of the high-strength, tightly fiber-braided and thick-walled WHAMs.

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