Prediction of Failure Pressure of Corroded Pipelines Based on Finite Element Analysis

2008 ◽  
Author(s):  
Jian Shuai ◽  
Chun’e Zhang ◽  
Fulai Chen ◽  
Renyang He
Keyword(s):  
Finite Element ◽  
Assessment Method ◽  
Element Analysis ◽  
Element Mesh ◽  
Linear Solution ◽  
Failure Pressure ◽  
Pipe Burst ◽  
Non Linear ◽  
Satisfactory Precision ◽  
New Formula

A numerical model for predicting the burst failure of corroded pipeline is constructed using the non-linear finite element method, in which the technical points including element mesh, materials model, non-linear solution and failure criterion are recommended. Using this model, the full-size pipe burst experiments in different material, size and defect was analyzed and computed. The proposed FEM model was validated. Based on the calculation result using the model, a new formula predicting failure pressure is proposed, in which depth, length and width of a defect was involved. Comparison of the formula with the other assessment method and experiments show the formula had a satisfactory precision.

Evaluating the Failure Pressure of Corroded Pipeline

2010 ◽  
Author(s):  
Jian Shuai
Keyword(s):  
Assessment Method ◽  
The Other ◽  
Fem Model ◽  
Full Size ◽  
Failure Pressure ◽  
Burst Test ◽  
Linear Finite Element ◽  
Pipe Burst ◽  
Satisfactory Precision ◽  
New Formula

This paper presented a review on ASME B31G, DNV RP-F101 and PCORRC methods in evaluating the remaining strength of corroded pipeline. These methods are validated by 67 sets of data about full-scale burst test of pipe with a defect. A numerical model for predicting the burst failure of corroded pipeline was constructed using the non-linear finite element method. Using this model, the full-size pipe burst experiments of pipelines in different material, size and defect was analyzed and computed. The proposed FEM model was validated. Based on the calculation result using the model, a new formula predicting failure pressure was presented, in which depth, length and width of a defect was involved. Comparison of the formula with the other assessment method and experiments showed the formula had a satisfactory precision.

Integrity Assessment of API 5L X65 and X70 Pipelines With Mechanical Damages

2012 ◽  
Author(s):  
Kyu Jung Yeom ◽  
Yong Kwang Lee ◽  
Kyu Hwan Oh ◽  
Cheol Man Kim ◽  
Woo Sik Kim
Keyword(s):  
Finite Element ◽  
Structural Integrity ◽  
Mechanical Damage ◽  
Local Stress ◽  
Assessment Method ◽  
Full Scale ◽  
Burst Pressure ◽  
Element Analysis ◽  
Integrity Assessment ◽  
Failure Pressure

Gas pipelines with mechanical damages could affect the structural integrity and causes local stress and strain concentration. Failures in gas pipeline as leakages that could affect the supply of gas, loss of production, and environmental pollution. It is important to determine if pipelines are fitness-for-service. ASME B31G code is still widely used criterion although the assessment method is the conservative method. Further examinations are needed on the effects of material grade and pipeline shape on the burst pressure of damaged pipelines. The goal of this paper is to predict the failure pressure of mechanical damaged made of API X65 and X70 pipelines, by conducting full scale burst tests and finite element analysis (FEA). Different pipeline grades, effects of gouges, and dent depths were considered for an integrity assessment. The full scale burst tests were performed for pipelines with artificial mechanical damage. The gouge defect was made in a V-notch shape and the dented pipeline was generated using a ball shaped indenter that was pressed into the pipe. A three dimensional FEA was performed to obtain the burst pressure of a pipe with gouge and dent defects as a function of defect depth and length. A FEA was used to simulate the and externally damaged pipes under internal pressure. Failure pressure was predicted with stress based and strain based assessments by the finite element method (FEM).

Investigations Into Fatigue Performance of Offshore Mooring Chains

2017 ◽  
Author(s):  
Gary H. Farrow ◽  
Andrew E. Potts ◽  
Daniel G. Washington
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fatigue Life ◽  
Fatigue Test ◽  
Test Data ◽  
Assessment Method ◽  
Accurate Estimate ◽  
Element Analysis ◽  
Factors Influencing ◽  
Non Linear

The Chain Finite Element Analysis of Residual Strength Joint Industry Project (Chain FEARS JIP) aimed to develop guidance for the determination of a rational discard criteria for mooring chains subject to severe pitting corrosion which would otherwise require immediate removal and replacement. Critical to the ability to evaluate the residual fatigue life of a degraded chain, is to have an accurate estimate of the chain in its as-new condition, thereby providing a benchmark for any loss in fatigue life associated with severe corrosion or wear. A non-linear multi-axial Finite Element Analysis (FEA) fatigue assessment method was developed and correlated against available fatigue test data as part of the JIP achieving this critical requirement. The development of this correlated methodology necessitated a review of: • The available mooring chain fatigue test data, to identify the factors influencing chain fatigue life and failure location. • FEA fatigue methodologies currently employed in the industry. • Current Class Rules relating to fatigue estimation. • The influence of material, manufacturing and operational factors on chain fatigue life. It was established that while the linear FEA fatigue method currently employed in the industry does not correlate with the fatigue test data, the non-linear multi-axial FEA fatigue method developed in the JIP afforded good correlation with test data. It was also demonstrated that the magnitude of mean chain tension and inconsistency in proof loading, as a consequence of the inconsistency in Class Minimum Break Load (MBL) specification, and with respect to chain size and the varying material ductility of steel grades, effects fatigue life. The identified inconsistency in the proofing indicates a likely inconsistency in conservatism embodied in the Class Rules fatigue formulation. Consequently it is possible that chains of certain size and grade may have significantly less fatigue life than anticipated by Class. Further work is recommended to establish a more rational proof load specification and to develop an alternative Class Rules fatigue formulation accounting for the identified factors influencing fatigue.

Integration of Laser Surface Scanning and Non-Linear Finite Element Analysis for the Assessment of Volumetric Corrosion in Pipeline Fittings

2014 ◽  
Author(s):  
Robert M. Andrews ◽  
Matthew Hadden ◽  
Paul Casson ◽  
Tamsin Kashap ◽  
Steven A. Johnstone
Keyword(s):  
Finite Element ◽  
Surface Profile ◽  
Initial Study ◽  
Large Strains ◽  
Fe Model ◽  
Element Analysis ◽  
Artificial Defect ◽  
Failure Pressure ◽  
Numerical Predictions ◽  
Non Linear

Methods for assessing volumetric corrosion in fittings such as bends or branch connections are not well developed, although limited guidance is given in some codes. For other components and cases where the corrosion profile is complex or there are large external loads, these methods cannot be applied. In addition, detailed analysis of the actual corrosion shape and the applied loads may demonstrate significant additional margins compared with the code method. To do this, the actual profile of the corroded shape is required. This paper reports an initial study investigating methods of non-contact scanning a corroded fitting, constructing a finite element (FE) model of the corroded shape and prediction of the failure pressure. Two corroded welded branch connections which had been removed from a block valve installation were used. The surface profiles were measured using a laser scanner and the scans imported into a FE model generation system and detailed models of the damaged connections then developed. Non-linear analyses were carried out to predict the failure pressure using assumed and measured stress-strain curves. Failure was predicted to occur in the area of the weld between the forged connection and the header. Hydrostatic burst tests were carried out on the connections. In both tests failure initiated in the header pipe remote from the branch and the corroded area, and as a result the failure pressures were below those predicted by the FEA. However, the failures did occur at pressures about 20% higher than the original hydrostatic test pressure. Strain gauge data from the pressure tests were in reasonable agreement with the numerical predictions. Large strains were predicted and measured in the large artificial defect introduced in the second test. This program has demonstrated the feasibility of making detailed surface profile measurements of corroded components on site, and then using these profiles in a non-linear FEA to predict failure pressures. The development work needed for routine application is discussed, and the selection of a failure criterion for the FEA when analysing complex geometries where there may be substantial through wall bending is also considered.

Behaviour of Axially Loaded Composite Wall Panel by Using Finite Element Analysis

2015 ◽  
Vol 815 ◽  
pp. 49-53
Author(s):  
Nur Fitriah Isa ◽  
Mohd Zulham Affandi Mohd Zahid ◽  
Liyana Ahmad Sofri ◽  
Norrazman Zaiha Zainol ◽  
Muhammad Azizi Azizan ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Composite Structures ◽  
Element Analysis ◽  
Steel Sheets ◽  
Linear Behavior ◽  
Non Linear ◽  
Composite Wall ◽  
Experimental Values ◽  
Civil Engineering Infrastructure

In order to promote the efficient use of composite materials in civil engineering infrastructure, effort is being directed at the development of design criteria for composite structures. Insofar as design with regard to behavior is concerned, it is well known that a key step is to investigate the influence of geometric differences on the non-linear behavior of the panels. One possible approach is to use the validated numerical model based on the non-linear finite element analysis (FEA). The validation of the composite panel’s element using Trim-deck and Span-deck steel sheets under axial load shows that the present results have very good agreement with experimental references. The developed finite element (FE) models are found to reasonably simulate load-displacement response, stress condition, giving percentage of differences below than 15% compared to the experimental values. Trim-deck design provides better axial resistance than Span-deck. More concrete in between due to larger area of contact is the factor that contributes to its resistance.

Elasto-Plastic Coupled Temperature-Displacement Finite Element Analysis of Two-Dimensional Rolling-Sliding Contact With a Translating Heat Source

1991 ◽  
Vol 113 (1) ◽  
pp. 93-101 ◽  
Author(s):  
S. M. Kulkarni ◽  
C. A. Rubin ◽  
G. T. Hahn
Keyword(s):  
Finite Element ◽  
Half Space ◽  
Plastic Material ◽  
Element Model ◽  
Rolling Contact ◽  
Two Dimensional ◽  
Element Analysis ◽  
Element Mesh ◽  
Perfectly Plastic ◽  
Elastic Perfectly Plastic

The present paper, describes a transient translating elasto-plastic thermo-mechanical finite element model to study 2-D frictional rolling contact. Frictional two-dimensional contact is simulated by repeatedly translating a non-uniform thermo-mechanical distribution across the surface of an elasto-plastic half space. The half space is represented by a two dimensional finite element mesh with appropriate boundaries. Calculations are for an elastic-perfectly plastic material and the selected thermo-physical properties are assumed to be temperature independent. The paper presents temperature variations, stress and plastic strain distributions and deformations. Residual tensile stresses are observed. The magnitude and depth of these stresses depends on 1) the temperature gradients and 2) the magnitudes of the normal and tangential tractions.

Specimen positioning effect on microshear test: Non-linear finite element analysis

2012 ◽  
Vol 28 ◽  
pp. e15-e16
Author(s):  
L.H.A. Raposo ◽  
L.C.M. Dantas ◽  
T.A. Xavier ◽  
A.G. Pereira ◽  
A. Versluis ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Element Analysis ◽  
Linear Finite Element ◽  
Non Linear

A Finite Element Analysis for Magnetostrictive Thin Film Structures and Its Experimental Verification

2006 ◽  
Vol 306-308 ◽  
pp. 1151-1156 ◽  
Author(s):  
Chong Du Cho ◽  
Heung Shik Lee ◽  
Chang Boo Kim ◽  
Hyeon Gyu Beom
Keyword(s):  
Thin Film ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Geometric Feature ◽  
Hysteresis Phenomenon ◽  
Finite Element Code ◽  
Element Analysis ◽  
Element Mesh ◽  
Magnetostrictive Actuators ◽  
Large Length

In this paper, a finite element code especially for micro-magnetostrictive actuators was developed. Two significant characteristics of the presented finite element code are: (1) the magnetostrictive hysteresis phenomenon is effectively taken into account; (2) intrinsic geometric feature of typical thin film structures of large length to thickness ratio, which makes it very difficult to construct finite element mesh in the region of the thin film, is considered reasonably in modeling micro-magneostrictive actuators. For verification purpose, magnetostrictive thin films were fabricated and tested in the form of a cantilevered actuator. The Tb-Fe film and Sm-Fe film are sputtered on the Si and Polyimide substrates individually. The magnetic and magnetostrictive properties of the sputtered magnetostrictive films are measured. The measured magnetostrictive coefficients are compared with the numerically calculated ones.

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