Experimental Database for Corroded Pipe: Evaluation of RSTRENG and B31G

2000 ◽  
Author(s):  
Duane S. Cronin ◽  
Roy J. Pick
Keyword(s):  
Tensile Tests ◽  
Line Pipe ◽  
Experimental Database ◽  
Corrosion Defect ◽  
Defect Assessment ◽  
Simple Geometry ◽  
Corrosion Defects ◽  
Failure Predictions ◽  
External Corrosion ◽  
Assessment Procedures

The evaluation and development of the current corrosion defect assessment procedures for pipelines has been based on experimental burst tests of line pipe. In these tests, external corrosion has often been simulated with machined defects of simple geometry. As a result, assessment procedures which model the corrosion defect geometry with only a few parameters, such as ASME B31G, show reasonable agreement with the experiments. However, the degree of conservatism in these assessment methods is undefined when they are applied to complex corrosion defects. The authors have burst over 40 pipes removed from service due to corrosion defects. All corrosion defects on each pipe were measured in detail and the material properties were determined from tensile tests. The currently accepted assessment procedures for corroded line pipe (B31G and RSTRENG) have been applied to the database. The degree of conservatism in these procedures is quantified and a statistical model for the failure predictions is proposed.

scholarly journals A New Multi-Level Assessment Procedure for Corroded Line Pipe

2000 ◽  
Author(s):  
Duane S. Cronin ◽  
Roy J. Pick
Keyword(s):  
Three Dimensional ◽  
Strain Curve ◽  
Tensile Tests ◽  
Assessment Method ◽  
Uniaxial Tensile ◽  
Assessment Procedure ◽  
Element Analysis ◽  
Line Pipe ◽  
Experimental Database ◽  
Multi Level

A new assessment method to predict the failure pressure of corrosion defects in line pipe has been developed. Comparison to an experimental database shows that this new assessment procedure has advantages over existing techniques. The implementation of this method is proposed in a multi-level assessment procedure. The assessment levels are organized in terms of increasing complexity, with Level I being a lower bound solution and requiring only the maximum defect depth. The new assessment method requires detailed corrosion geometry measurements and is proposed as a Level II. Three dimensional elastic-plastic finite element analysis is proposed for the Level III. These methods assume the true stress-strain curve of the material is known, which can be determined from uniaxial tensile tests. When these material properties are unknown, the currently accepted codes are suggested for defect evaluation.

Finite Element Analysis of Complex Corrosion Defects

2002 ◽  
Author(s):  
Duane S. Cronin
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Burst Pressure ◽  
Uniaxial Tensile ◽  
Element Analysis ◽  
Internal Corrosion ◽  
Corrosion Defect ◽  
Elastic Plastic ◽  
Defect Assessment ◽  
Corrosion Defects

Aging gas and oil transmission pipeline infrastructure has led to the need for improved integrity assessment. Presently, external and internal corrosion defects are the leading cause of pipeline failure in Canada, and in many other countries around the world. The currently accepted defect assessment procedures have been shown to be conservative, with the degree of conservatism varying with the defect dimensions. To address this issue, a multi-level corrosion defect assessment procedure has been proposed. The assessment levels are organized in terms of increasing complexity; with three-dimensional elastic-plastic Finite Element Analysis (FEA) proposed as the highest level of assessment. This method requires the true stress-strain curve of the material, as determined from uniaxial tensile tests, and the corrosion defect geometry to assess the burst pressure of corrosion defects. The use of non-linear FEA to predict the failure pressure of real corrosion defects has been investigated using the results from 25 burst tests on pipe sections removed from service due to the presence of corrosion defects. It has been found that elastic-plastic FEA provides an accurate prediction of the burst pressure and failure location of complex-shaped corrosion defects. Although this approach requires detailed information regarding the corrosion geometry, it is appropriate for cases where an accurate burst pressure prediction is necessary.

Development of an Alternative Criterion for Residual Strength of Corrosion Defects in Moderate- to High-Toughness Pipe

2000 ◽  
Author(s):  
Denny R. Stephens ◽  
Brian N. Leis
Keyword(s):  
Model Development ◽  
Plastic Collapse ◽  
Analysis Model ◽  
Line Pipe ◽  
Experimental Database ◽  
Software Analysis ◽  
Finite Element Software ◽  
High Toughness ◽  
Repair Costs ◽  
Corrosion Defects

This paper presents the development of a new, simplified criterion, known as PCORRC, for prediction of the remaining strength of corrosion defects in moderate- to high-toughness pipeline steels that fail by plastic collapse. Comparisons against an experimental database indicate that, when toughness is sufficient, the PCORRC criterion reliably predicts the remaining strength of blunt defects using only the maximum depth and maximum length of the defects with less excess conservatism than existing criteria. The value of PCORRC is demonstrated in comparisons that show it capable of reducing excess conservatism significantly in the class of defects that fail by plastic collapse, potentially resulting in significant reductions in pipeline maintenance and repair costs. This new criterion was developed at Battelle under sponsorship of the Line Pipe Research Supervisory Committee of PRC international. The new simplified criterion was developed from a finite-element software analysis model. The analysis software was applied in a parametric investigation to evaluate the influence of geometry and material characteristics on the remaining strength of corrosion defects in moderate- to high-toughness steels that fail by plastic collapse. The model development and parametric investigations demonstrated that: • The failure of this class of defects is controlled by the ultimate tensile strength rather than yield strength or flow stress; • Defect depth and length are the most critical defect geometry variables; • Defect width and material strain hardening are of lesser importance.

Crack in Corrosion Defect Assessment in Transmission Pipelines

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
A. Hosseini ◽  
D. Cronin ◽  
A. Plumtree
Keyword(s):  
Crack Depth ◽  
Evaluation Criteria ◽  
Average Error ◽  
Failure Behavior ◽  
Pipe Material ◽  
Line Pipe ◽  
Collapse Pressure ◽  
Defect Assessment ◽  
Level 3 ◽  
Corrosion Defects

Cracks may occur coincident with corrosion representing a new hybrid defect in gas and oil pipelines known as crack in corrosion (CIC) that is not directly addressed in the current codes or assessment methods. Hence, there is a need to provide an assessment of CIC and evaluate the line integrity, as well as identify the requirements for defect repair or line hydrotest. An experimental investigation was undertaken to evaluate the collapse pressures of lines containing corrosion, cracks, or (CIC) defects in a typical line pipe (API 5L Grade X52, 508 mm diameter, 5.7 mm wall thickness). The mechanical properties of the pipe were measured using tensile, Charpy, and J-testing for use in applying evaluation criteria. Rupture tests were undertaken on end-capped sections containing uniform depth, finite length corrosion, cracks, or CIC defects. Failure occurred by plastic collapse and ductile tearing for the corrosion defects, cracks, and CIC geometries tested. For the corrosion defects, the corroded pipe strength (CPS) method provided the most accurate results (13% conservative on average). The API 579 (level 3 failure assessment diagram (FAD), method D) provided the least conservative collapse pressure predictions for the cracks with an average error of 20%. The CIC collapse pressures were bounded by those of a long corrosion groove (upper bound) and a long crack (lower bound), with collapse dominated by the crack when the crack depth was significant. Application of API 579 to the CIC provided collapse pressure predictions that were 18% conservative. Sixteen rupture tests were successfully completed investigating the failure behavior of longitudinally oriented corrosion, crack, and CIC. The pipe material was characterized and these properties were used to predict the collapse pressure of the defects using current methods. Existing methods for corrosion (CPS) and cracks (API 579, level 3, method D) gave conservative collapse pressure predictions. The collapse pressures for the CIC were bounded by those of a long corrosion groove and a long crack, with collapse dominated by the crack when the crack depth was significant. CIC failure behavior was determined by the crack to corrosion depth ratio, total defect depth and its profile. The results showed that the failure pressures for CIC were reduced when their equivalent depths were similar to those of corrosion and using crack evaluation techniques provided an approximate collapse pressure.

Assessment of Crack in Corrosion Defects in Natural Gas Transmission Pipelines

2008 ◽  
Author(s):  
Duane Cronin ◽  
Alan Plumtree ◽  
Millan Sen ◽  
Richard Kania
Keyword(s):  
Numerical Investigation ◽  
Finite Length ◽  
Defect Depth ◽  
Hybrid Form ◽  
Line Pipe ◽  
Collapse Pressure ◽  
Corrosion Defect ◽  
Natural Gas Transmission ◽  
Defect Repair ◽  
Corrosion Defects

Crack-like defects may occur coincident with corrosion defects and represent a new hybrid form of defect in gas and oil pipelines that is not directly addressed in the current codes or methods of assessment. There is a need to provide assessment and evaluate the integrity of the line as well as identify requirements for defect repair or line hydrotest. A numerical investigation was undertaken to evaluate the predicted collapse pressure of crack in corrosion (CIC) defects in typical line pipe. Longitudinally oriented CIC defects were evaluated as long cracks occurring within long, corrosion grooves of uniform depth. This was a conservative representation of a finite length CIC defect. It was found that the collapse pressure for CIC defects varied between that of a long uniform depth crack and a long uniform depth corrosion defect. The transition to corrosion defect behaviour only occurred when the corrosion defect depth was significant (greater than 75% of the total defect depth). Finite-length CIC defects were then investigated using a numerical investigation to identify the effect of crack and corrosion length. The collapse pressure of a finite length crack within an infinitely long corrosion defect was found to be lower than a crack of equivalent total depth and length. This reduction in collapse pressure was attributed to increased local stresses in the vicinity of the crack due to the coincident corrosion. The predicted collapse pressure increased towards the crack-only value when the length of the corrosion defect was decreased to that of the crack. CIC defects were evaluated as cracks using the NG-18 approach and BS 7910 code (Level 2A FAD). The NG-18 approach conservatively predicted lower collapse pressures than the FE analysis, whereas the FAD approach was conservative for shallow defects and could be non-conservative for deeper defects. These results are attributed to the presence of the corrosion and the fact that no factor of safety was included in the analysis. Future studies will investigate experimental validation of the FE and FAD methods for this type of defect.

Making use of external corrosion defect assessment (ECDA) data to predict DCVG %IR drop and coating defect area

2018 ◽  
Vol 69 (9) ◽  
pp. 1237-1256 ◽  
Author(s):  
Nik N. Bin Muhd Noor ◽  
Keming Yu ◽  
Ujjwal Bharadwaj ◽  
Tat-Hean Gan
Keyword(s):  
Corrosion Defect ◽  
Ir Drop ◽  
Defect Assessment ◽  
Defect Area ◽  
Coating Defect ◽  
External Corrosion

Characterisation of the plane anisotropy and its effect on interstitial free steel thin sheet metal forming simulation

2021 ◽  
pp. 146442072110534
Author(s):  
Latifa Arfaoui ◽  
Amel Samet ◽  
Amna Znaidi
Keyword(s):  
Thin Sheet ◽  
Rolling Direction ◽  
Tensile Tests ◽  
Interstitial Free ◽  
Experimental Database ◽  
Forming Simulation ◽  
Hardening Law ◽  
Tension Tests ◽  
Interstitial Free Steel ◽  
Thin Sheet Metal

The main purpose of this paper is to study the orthotropic plastic behaviour of the cold-rolled interstitial free steel HC260Y when it is submitted to various loading directions under monotonic tests. The experimental database included tensile tests carried out on specimens (in the as-received condition and after undergoing an annealing heat treatment) cut in different orientations according to the rolling direction. A model was proposed, depending on a plasticity criterion, a hardening law and an evolution law, which takes into account the anisotropy of the material. To validate the proposed identification strategy, a comparison with the experimental results of the planar tension tests, carried out on specimens cut parallel to the rolling direction, was considered. The obtained results allowed the prediction of the behaviour of this material when it is subjected to other solicitations whether simple or compound.

Mechanical and thermal behaviors of ultra-high molecular weight polyethylene triaxial braids: the influence of structural parameters

2018 ◽  
Vol 89 (16) ◽  
pp. 3362-3373 ◽  
Author(s):  
Shenglei Xiao ◽  
Charles Lanceron ◽  
Peng Wang ◽  
Damien Soulat ◽  
Hang Gao
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Mechanical Characteristics ◽  
Structural Parameters ◽  
Tensile Tests ◽  
Tensile Behavior ◽  
Experimental Database ◽  
Strength And Deformation ◽  
Braiding Angle ◽  
Ultra High Molecular Weight

Recently, triaxial braids made from ultra-high molecular weight polyethylene (UHMWPE) have been recognized as one of the most popular composite reinforcements in the aerospace and defense fields. To further explore the mechanical characteristics of this material, a detailed experimental study on tensile behavior is reported in this paper. The triaxial braids show a “double-peak” phenomenon in tensile strength and deformation, caused by axial yarns and the in-plane shearing of bias yarns. The evolution of the braiding angle, measured during these tensile tests, is discussed according to the braiding parameters (initial braiding angle, number of axial yarns). Using the high conductivity properties of the UHMWPE material, the temperature caused by inter-yarn friction during tensile tests is also studied. This temperature is related to the evolution of the braiding angle. The temperature increases with the increasing number of axial yarns and decreases with increasing braiding angle. This study provides an experimental database on the influence of braiding parameters on the tensile behavior of triaxial braids.

RCC-MRx Appendix A16 Methodology for the Analytical J Calculation Under Thermal and Combined Thermal + Mechanical Loadings for Pipes and Elbows and Related Assessment Tool MJSAM

2011 ◽  
Author(s):  
S. Marie ◽  
M. Ne´de´lec ◽  
C. Delaval
Keyword(s):  
Nuclear Power ◽  
Assessment Tool ◽  
Analytical Calculation ◽  
Large Set ◽  
Microsoft Excel ◽  
Defect Assessment ◽  
Initiation And Propagation ◽  
Creep Fatigue ◽  
Assessment Procedures ◽  
2D And 3D

RCC-MRx code provides flaw assessment methodologies and related tools for Nuclear Power Plant cracked components. An important work has been made in particular to develop a large set of compendia for the calculation of the parameter J for various components (plates, pipes, elbows,…) and various defect geometries. Also, CEA in the frame of collaborations with IRSN, developed a methodology for J analytical calculation for cracked pipes and elbows submitted to thermal and combined mechanical and thermal loadings. This paper presents first the development of this methodology and an overview of the validation strategy, based on reference 2D and 3D F.E. calculations. The second part of the paper presents the last version of the MJSAM tools which is based on the 2010 version of the appendix A16 of the RCC-MRx code. All compendia (for KI, J and C* calculation) and all defect assessment procedures have been implemented in the tool: It covers crack initiation and propagation under fatigue, creep, creep-fatigue and ductile tearing situations. Sensitivity and probabilistic analyses can also been performed with this tool, directly linked to Microsoft Excel software for the results exploitation.

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