Deformation Behavior Prediction of X80 Steel Line Pipe and Implication on High Strain Pipe Specification

2008 ◽  
Author(s):  
Hongyuan Chen ◽  
Lingkang Ji ◽  
Shaotao Gong ◽  
Huilin Gao
Keyword(s):  
Internal Pressure ◽  
Material Properties ◽  
High Strain ◽  
Behavior Prediction ◽  
Buckling Mode ◽  
Line Pipe ◽  
Geometric Imperfection ◽  
China National Petroleum Corporation ◽  
Scale Test ◽  
Pipe Size

The use of strain based design in pipeline technology has been widely discussed during the last decade for pipelines in harsh environment. In such cases pipelines should be designed based on strain criterion. Strain based design poses a number of challenges, particularly on pipe size and material properties. This paper presents preliminary studies on prediction of buckling strain and buckling mode for X80 high-strain line pipe by finite element methods based on full-scale test. The effects of several parameters such as internal pressure, material properties pipe size and geometric imperfection, were investigated to predict the critical strain for 48″ diameter line pipe under compression and pure bending with 12MPa internal pressure. Material parameters of a specification for high strain line pipe were analyzed to promote its application in the 2nd West-East pipeline of China National Petroleum Corporation.

scholarly journals Analysis for Wrinkling Behavior of Girth-Welded Line Pipe

1996 ◽  
Author(s):  
Luiz T. Souza ◽  
David W. Murray
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Finite Element Model ◽  
Internal Pressure ◽  
Experimental Test ◽  
Element Model ◽  
Element Analysis ◽  
Line Pipe ◽  
New Era ◽  
Analytical Tools

The paper presents results for finite element analysis of full-sized girth-welded specimens of line pipe and compares these results with the behavior exhibited by test specimens subjected to constant axial force, internal pressure and monotonically increasing curvatures. Recommendations for the ‘best’ type of analytical finite element model are given. Comparisons between the behavior predicted analytically and the observed behavior of the experimental test specimens are made. The mechanism of wrinkling is explained and the evolution of the deformed configurations for different wrinkling modes is examined. It is concluded that the analytical tools now available are sufficiently reliable to predict the behavior of pipe in a manner that was not previously possible and that this should create a new era for the design and assessment of pipelines if the technology is properly exploited by industry.

Girth Weld Strength Matching Effect on Tensile Strain Capacity of Grade X70 High Strain Line Pipe

2018 ◽  
Author(s):  
Hisakazu Tajika ◽  
Takahiro Sakimoto ◽  
Tsunehisa Handa ◽  
Rinsei Ikeda ◽  
Joe Kondo
Keyword(s):  
High Strain ◽  
Limit State ◽  
Full Scale ◽  
Bending Test ◽  
High Grade ◽  
Line Pipe ◽  
Bending Tests ◽  
Strain Capacity ◽  
Pipeline Project ◽  
Pipe Bending

Recently high grade pipeline project have been planned in hostile environment like landslide in mountain area, liquefaction in reclaimed land or the frost heave in Polar Regions. Geohazards bring large scale ground deformation and effect on the varied pipeline to cause large deformation. Therefore, strain capacity is important for the pipeline and strain based design is also needed to keep gas transportation project in safe. High grade steel pipe for linepipe tends to have higher yield to tensile (Y/T) ratio and it has been investigated that the lower Y/T ratio of the material improves strain capacity in buckling and tensile limit state. In onshore pipeline project, pipe usually transported in 12 or 18m each and jointed in the field. Girth weld (GW) is indispensable so strength matching of girth weld towards pipe body is important. In this study strain capacity of Grade X70 high strain pipes with size of 36″ OD and 23mm WT was investigated with two types of experiments, which are full scale pipe bending tests and curved wide plate tests. The length of the specimen of full scale bending tests were approximately 8m and girth weld was made in the middle of joint length. A fixed internal pressure was applied during the bending test. Actual pipe situation in work was simulated and both circumferential and longitudinal stress occurred in this test. Test pipes were cut and welded, GTAW in first two layer and then finished by GMAW. In one pipe, YS-TS over-matching girth weld (OVM) joint was prepared considering the pipe body grade. For the other pipe, intentionally under-matching girth weld (UDM) joint was prepared. After the girth welding, elliptical EDM notch were installed in the GW HAZ as simulated weld defect. In both pipe bending tests, the buckling occurred in the pipe body at approximately 300mm apart from the GW and after that, deformation concentrated to buckling wrinkle. Test pipe breaking locations were different in the two tests. In OVM, tensile rupture occurred in pipe body on the backside of buckling wrinkle. In UDM, tensile rupture occurred from notch in the HAZ. In CWP test, breaking location was the HAZ notch. There were significant differences in CTOD growth in HAZ notch in these tests.

Analysis of Nonlinear Buckling of a Long-Span Elliptic Paraboloid Suspended Dome Structure

2013 ◽  
Vol 639-640 ◽  
pp. 191-197 ◽  
Author(s):  
Zheng Rong Jiang ◽  
Kai Rong Shi ◽  
Xiao Nan Gao ◽  
Qing Jun Chen
Keyword(s):  
Single Layer ◽  
Buckling Mode ◽  
Nonlinear Buckling ◽  
Elliptic Paraboloid ◽  
Geometric Imperfection ◽  
Long Span ◽  
Initial Geometric Imperfection ◽  
Dome Structure ◽  
Unsymmetrical Loading ◽  
The Stability

The suspended dome structure, which is a new kind of hybrid spatial one composed of the upper single layer latticed shell and the lower cable-strut system, generally has smaller rise-to-span ratio, thus the overall stability is one of the key factors to the design of the structure. The nonlinear buckling behavior of an elliptic paraboloid suspended dome structure of span 110m80m is investigated by introducing geometric nonlinearity, initial geometric imperfection, material elastic-plasticity and half-span distribution of live loads. The study shows that the coefficient of stable bearing capacity usually is not minimal when the initial geometric imperfection configuration is taken as the first order buckling mode. The unsymmetrical loading distribution and the material nonlinearity might have significant effects on the coefficient. The structure is sensitive to the changes of initial geometric imperfection, and the consistent mode imperfection method is not fully applicable to the stability analysis of suspended dome structure.

Behavior and Design of Web-Slotted Cold-Formed Channels Experiencing Local-Distortional-Global Interactive Buckling

2013 ◽  
Vol 351-352 ◽  
pp. 747-752
Author(s):  
Shuai Liu ◽  
Qi Jie Ma ◽  
Pei Jun Wang
Keyword(s):  
Effective Width ◽  
The Finite Element Method ◽  
Distortional Buckling ◽  
Buckling Mode ◽  
Geometric Imperfection ◽  
Interactive Behavior ◽  
Buckling Behavior ◽  
Initial Geometric Imperfection ◽  
Interactive Buckling ◽  
Shed Light

This article aims to shed light on the nonlinear local-distortional-global interactive behavior of web-slotted channel columns by use of the finite element method. The effects of three kinds of initial geometric imperfection based on different distortional buckling mode were evaluated. It indicates that different distortional buckling mode does little difference on the nonlinear interactive buckling behavior of web-slotted channels. Based on the extensive parametric study, some modifications were made to the traditional Effective Width Method for the practical design of web-slotted channel columns undergoing local-distortional-global interactive buckling.

Low Circle Fatigue Behavior of X80 High-Strain Line Pipe

ICPTT 2012 ◽  
2012 ◽  
Author(s):  
Yang Li ◽  
Weiwei Zhang ◽  
Lingkang Ji ◽  
Qingren Xiong ◽  
Yaorong Feng ◽  
...  
Keyword(s):  
High Strain ◽  
Fatigue Behavior ◽  
Line Pipe

Burst Tests on Pipeline Containing Circumferential Corrosion Defects

2010 ◽  
Author(s):  
Adilson C. Benjamin ◽  
Jose´ Luiz F. Freire ◽  
Ronaldo D. Vieira ◽  
Jorge L. C. Diniz
Keyword(s):  
Internal Pressure ◽  
Material Properties ◽  
Impact Test ◽  
Tubular Specimen ◽  
Spark Erosion ◽  
X80 Steel ◽  
Corrosion Defects ◽  
Circumferential Defects ◽  
Tubular Specimens ◽  
Outside Diameter

Circumferential defects are the ones in which the width w is greater than the length L (w > L). In this paper the burst tests of three tubular specimens are presented. In these tests the tubular specimens were loaded with internal pressure only. The specimens were cut from longitudinal welded tubes made of API 5L X80 steel with a nominal outside diameter of 457.2 mm (18 in) and a nominal wall thickness of 7.93 mm (0.312 in). Each of the three specimens had one external circumferential corrosion defect, machined using spark erosion. Measurements were carried out in order to determine the actual dimensions of each tubular specimen and its respective defect. Tensile specimens and impact test specimens were tested to determine material properties. The failure pressures measured in the burst tests are compared with those predicted by five assessments methods, namely: the ASME B31G method, the RSTRENG 085dL method, the DNV RP-F101 method for single defects (Part B), the RPA method and the Kastner equation.

Mass Production and Installation of X100 Linepipe for Strain-Based Design Application

2008 ◽  
Author(s):  
Nobuyuki Ishikawa ◽  
Mitsuhiro Okatsu ◽  
Shigeru Endo ◽  
Joe Kondo ◽  
Joe Zhou ◽  
...  
Keyword(s):  
Base Metal ◽  
Material Properties ◽  
Mass Production ◽  
High Strain ◽  
Uniform Elongation ◽  
Accelerated Cooling ◽  
Absorbed Energy ◽  
Strain Capacity ◽  
Weld Properties ◽  
Charpy Absorbed Energy

Continuous efforts have been made for the realization of strain-based design pipeline using high grade linepipe materials. Two demonstrative constructions of the pipelines using X100 linepipe proved sufficient materials properties for strain-based design and high quality field welding with good productivity. In order to verify further applicability of high strain X100 linepipe for long distance transmission, large scale installation of X100 pipeline was accomplished. Mass production of X100 linepipe of about 2,000 metric tons with the size of 42″OD and 14.3mm wall thick was successfully conducted by applying recent developed TMCP process including accelerated cooling and online heat treatment process and UOE pipe forming. Field girth welding was safely completed by the dual tandem pulsed GMAW, and sufficient girth weld properties were demonstrated. This paper will describe material development and mass production results of X100 linepipe for strain-based design which specifying longitudinal tensile properties such as Y/T ratio and uniform elongation. In order to securely specify the shape of stress-strain curve without Luders elongation, material parameter “stress ratio” was introduced for the material specification for compressive strain capacity. Stringent base metal requirements were imposed for base metal material properties in this project. One of the most challenging aspects in developing high strain linepipe is to balance uniform elongation and Charpy absorbed energy. Dual phase microstructure is essential to improve strain capacity, but this may lead to lower Charpy absorbed energy. Therefore, precise control of microstructure by controlling plate manufacturing parameter was required. In addition, on-line heating process subsequently after accelerated cooling enabled increase of Charpy energy without deteriorating uniform elongation. Girth weld properties were closely evaluated using the X100 pipe in as UOE condition and after external coating. All the material properties of base metal and girth weldment of the X100 linepipes used for this project fulfill the stringent requirement for strain-based design consideration to prevent buckling and weld fracture.

High Strain Rate Compressive Properties of Soft Tissue

2003 ◽  
Author(s):  
Caleb R. Van Sligtenhorst ◽  
Duane S. Cronin ◽  
G. Wayne Brodland
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
Material Properties ◽  
Fiber Orientation ◽  
Soft Tissues ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Strain Rates ◽  
Post Mortem ◽  
Fresh Tissue

High strain rate material properties and constitutive equations are essential for the development of numerical and physical models to assess the performance of soft materials subject to high rate deformation, with potential applications including protective equipment and vehicle crashworthiness. However, these properties are not available for many soft tissues. This is because specialized testing methods must be employed to obtain the necessary data. Fresh bovine tissue from the semimembranosis muscle was obtained and tested using a polymeric Split Hopkinson Pressure Bar. Samples were tested from 1.4 to 200 hours post mortem to observe the effect of rigor and other possible temporal effects on the material properties. Since this muscle had relatively uniform fiber orientation, it was possible to obtain specimens with fiber directions parallel, perpendicular, and at 45 degrees to the compression axis. The stress-strain curves for the muscle were concave upwards, as is typical of soft tissues at high strain rates. Fiber orientation was determined to have negligible effect at the tested strain rates. The testing revealed that the stiffness of the tissue increased with post mortem time until approximately 6 hours. At times greater than 200 hours post mortem, the tissue properties were found to be very similar to the properties of fresh tissue. These findings suggest that properties of fresh tissue might be estimated using more easily obtained post-rigor tissue.

Effect of Material Properties on the Strain to Failure of Thick-Walled Cylinders Subjected to Internal Pressure

1994 ◽  
Vol 116 (2) ◽  
pp. 96-104 ◽  
Author(s):  
D. P. Roach ◽  
T. G. Priddy
Keyword(s):  
Internal Pressure ◽  
Material Properties ◽  
Maximum Pressure ◽  
Plastic Response ◽  
Empirical Formulas ◽  
Stress Strain Relation ◽  
Simple Tension ◽  
Bursting Pressures ◽  
Versus Strain

The determination of the fully plastic response and pressure limit of a pressure vessel is of considerable importance in design, especially in autofrettage considerations. This paper presents the results of an experimental study which measured the maximum internal pressure which can be applied to thick-walled cylindrical vessels. Both aluminum and steel, with material properties ranging from ductile to brittle, were tested at stress levels through plastic and strain hardening ranges to fracture. From these tests, the pressure-expansion and through-thickness yielding characteristics were determined for these specimens. It is shown that a strain-to-failure criterion, based on the triaxiality of stress in the critical region, can be used to predict the complete pressure versus strain relations and maximum pressure for these cylinders. A simple tension-true stress-strain relation of the material is employed to analytically predict the response of the cylinder into the plastic regime. Finally, simplified theoretical and empirical formulas for bursting pressures are checked against the experimental results.

Non-Linear Contact Analysis of an API Line Pipe Coupling

2009 ◽  
Author(s):  
Jeroen Van Wittenberghe ◽  
Patrick De Baets ◽  
Wim De Waele
Keyword(s):  
Material Properties ◽  
Element Model ◽  
Test Results ◽  
Line Pipe ◽  
Bending Fatigue ◽  
Material Parameters ◽  
Four Point Bending ◽  
Pipe Coupling ◽  
Contact Behaviour ◽  
The Finite Element Model

In this study, the finite element model of an API Line Pipe threaded pipe connection is presented. The non-linearities in material properties and contact behaviour are discussed. A series of modifications of the standard connection are simulated to gain a better understanding in the influence of geometrical and material parameters on the connection’s performance. Finally, test results obtained from a four-point bending fatigue experiment are presented and compared with numerical simulations.

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