Development of Leak Resistance in Industry Standard OCTG Connections using Finite Element Analysis and Full Scale Testing

Author(s):  
B.E. Schwind ◽  
M.L. Payne ◽  
G.K. Otten ◽  
P.D. Pattillo
Author(s):  
Dag Fergestad ◽  
Frank Klæbo ◽  
Jan Muren ◽  
Pål Hylland ◽  
Tom Are Grøv ◽  
...  

This paper discusses the structural challenges associated with high axial temperature gradients and the corresponding internal cross section forces. A representative flexible pipe section designed for high operational temperature has been subject to full scale testing with temperature profiles obtained by external heating and cooling. The test is providing detailed insight in onset and magnitude of relative layer movements and layer forces. As part of the full-scale testing, novel methods for temperature gradient testing of unbonded flexible pipes have been developed, along with layer force- and deflection-measurement techniques. The full-scale test set-up has been subject to numerous temperature cycles of various magnitudes, gradients, absolute temperatures, as well as tension cycling to investigate possible couplings to dynamics. Extensive use of finite element analysis has efficiently supported test planning, instrumentation and execution, as well as enabling increased understanding of the structural interaction within the unbonded flexible pipe cross section. When exploiting the problem by finite element analysis, key inputs will be correct material models for the polymeric layers, and as-built dimensions/thicknesses. Finding the balance between reasonable simplification and model complexity is also a challenge, where access to high quality full-scale tests and dissected pipes coming back from operation provides good support for these decisions. Considering the extensive full scale testing, supported by advanced finite element analysis, it is evident that increased attention will be needed to document reliable operation in the most demanding high temperature flexible pipe applications.


2014 ◽  
Vol 530-531 ◽  
pp. 251-255
Author(s):  
Jian Rong Yang ◽  
Yu Bai ◽  
Xiao Dong Yang ◽  
Wei Ming Zhu

Three dimension finite element analysis and full-scale testing are carried out on a newly-built self-anchored suspension bridge. The 3D finite element model of the bridge is generated using a commercially available finite element package. The bridge is modeled under service loads, and the model results are compared to the results of field testing of the structure. Detailed experimental procedure is presented including the data acquisition system, testing truck, and the load distribution. Measured and calculated displacements are in reasonable concordance. And residual deformations meet the specification of the codes, no cracking opening.


Author(s):  
Colton Sheets ◽  
Robert Rettew ◽  
Chris Alexander ◽  
Ashwin Iyer

Composite repair systems for pipelines are continuing to be used for increasingly difficult and complex applications which can have a high consequence of failure. In these instances, full-scale testing is typically pursued at a high-cost to the manufacturer or operator. Finite element analysis (FEA) modeling is a valuable tool that becomes especially attractive as a method to reduce the number of full-scale tests required. This is particularly true when considering the costs associated with recreating complex load and temperature conditions. In order for FEA to fill this role, it is necessary to validate the results through full-scale testing at the same loads and temperatures. By using these techniques, FEA and full-scale testing can be used in unison to efficiently produce accurate results and allow for the adjustment of critical parameters at a much lower cost than creating additional full-scale tests. For this program, a series of finite element analysis (FEA) models were developed to evaluate the performance of composite materials used to reinforce corroded steel pipe in critical applications at elevated temperatures up to 120 °C. Two composite repair manufacturers participated in the study which was conducted on 12-inch × 0.375-inch Gr. X60 pipes with machined simulated corrosion defects that represented 50% wall loss. Load conditions consisted of axial compressive loads or bending moments to generate compressive stresses in the machined defect. In the described evaluation program, FEA simulations were able to produce results which supported those found in full-scale validation testing. From the FEA models stresses and strains were extracted from the reinforced steel and composite materials. Good correlation was observed in comparing the results. Although limitations of the modeling included accurately capturing differential thermal strains introduced by the elevated test temperature, the results indicated that FEA models could be used as a cost-effective means for assessing composite repair systems in high-temperature applications.


2009 ◽  
Vol 374 (2) ◽  
pp. 93-103 ◽  
Author(s):  
Igor Tsukrov ◽  
Judson C. DeCew ◽  
Kenneth Baldwin ◽  
Regina Campbell-Malone ◽  
Michael J. Moore

Author(s):  
Celal Cakiroglu ◽  
Samer Adeeb ◽  
J. J. Roger Cheng ◽  
Millan Sen

Pipelines can be subjected to significant amounts of tensile forces due to geotechnical movements like slope instabilities and seismic activities as well as due to frost heave and thaw cycles in arctic regions. The tensile strain capacity εtcrit of pipelines is crucial in the prediction of rupture and loss of containment capability in these load cases. Currently the Oil and Gas Pipeline Systems code CSA Z662-11 0 contains equations for the prediction of εtcrit as a function of geometry and material properties of the pipeline. These equations resulted from extensive experimental and numerical studies carried out by Wang et al [2]–[6] using curved wide plate tests on pipes having grades X65 and higher. Verstraete et al 0 conducted curved wide plate tests at the University of Ghent which also resulted in tensile strain capacity prediction methods and girth weld flaw acceptability criteria. These criteria are included in the European Pipeline Research Group (EPRG) Tier 2 guidelines. Furthermore Verstrate et al 0 introduced a pressure correction factor of 0.5 in order to include the effect of internal pressure in the tensile strain capacity predictions in a conservative way. Further research by Wang et al with full scale pipes having an internal pressure factor of 0.72 also showed that εtcrit decreases in the presence of internal pressure [10]–[15]. In their work, Wang et al presented a clear methodology for the design of full scale experiments and numerical simulations to study the effect of internal pressure on the tensile strain capacity of pipes with girth weld flaws [10]–[15]. However, there has been limited testing to enable a precise understanding of the tensile strain capacity of pipes with grades less than X65 as a function of girth weld flaw sizes and the internal pressure. In this paper the experimental setup for the testing of grade X52 full scale specimens with 12″ diameter and ¼″ wall thickness is demonstrated. In the scope of this research 8 full scale specimens will be tested and the results will be used to formulate the tensile strain capacity of X52 pipes under internal pressure. The specimens are designed for the simultaneous application of displacement controlled tensile loading and the internal pressure. Finite element analysis is applied in the optimization process for the sizes of end plates and connection elements. Also the lengths of the full scale specimens are determined based on the results from finite element analysis. The appropriate lengths are chosen in such a way that between the location of the girth weld flaw and the end plates uniform strain zones could be obtained. The internal pressure in these experiments is ranging between pressure values causing 80% SMYS and 30% SMYS hoop stress. The end plates and connection elements of the specimens are designed in such a way that the tensile displacement load is applied with an eccentricity of 10% of the pipe diameter with the purpose of increasing the magnitude of tensile strains at the girth weld flaw location. The results of two full scale experiments of this research program are presented. The structural response from the experiments is compared to the finite element simulation. The remote strain values of the experiment are found to be higher than the εtcrit values predicted by the equations in 0.


Proceedings ◽  
2018 ◽  
Vol 2 (8) ◽  
pp. 520
Author(s):  
Jordi D’hondt ◽  
Sien Dieltiens ◽  
Marc Juwet

The present article describes the methodology used to design and calibrate a 6-component balance. This balance is utilized in an instrumented bike measuring the forces applied on the handlebars. This instrumentation bike maps all riders induced loads. In the designing process, Finite Element Analysis was used. Calibrating the balance was done using the Least Square Regression Method which allows combining multiple loads during calibration and thus requires less samples. The balance operates with a maximum full scale error of 0.53%.


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