scholarly journals Characterization of mechanical properties in weld metal using inverse modelling

2012 ◽  
Vol 3 (1) ◽  
pp. 19-24
Author(s):  
J. Beddeleem ◽  
W. De Waele ◽  
S. Hertelé ◽  
M. Verstraete ◽  
K. Van Minnebruggen
Keyword(s):  
Mechanical Properties ◽  
Weld Metal ◽  
Structural Integrity ◽  
Oil And Gas ◽  
Accurate Determination ◽  
Simulated Data ◽  
Element Model ◽  
Inverse Modelling ◽  
Full Field ◽  
Modelling Framework

Nowadays, more oil and gas transportation pipelines are constructed in areas with permafrost and/or higherseismic activity. These pipelines can be subjected to longitudinal plastic deformations necessitating a strainbased design. Since girth- and seam welds are critical in terms of structural integrity, it is desirable to knowtheir mechanical properties. In a strain based design context, the accurate determination of yield strengthand hardening are necessary. A longitudinally extracted (is parallel to the pipe axis) specimen notched atthe weld region and loaded in tension, in combination with inverse modelling is assumed to be a valuabletool to determine these properties. This notched cross weld test ensures that the largest deformations willoccur at the weld, thereby allowing to fully determine the stress-strain behaviour of the weld metal. Inversemodelling combines experimental full-field strain data with numerical simulations to determine theconstitutive parameters. Strains will be measured experimentally and compared with simulated data. Byminimizing their difference, i.e. a certain cost function, a correspondence is found and the desiredparameters are determined. This paper focuses on one aspect of the inverse modelling framework, thedevelopment of the parametric finite element model.

Experimental Analysis on Mechanical Properties of Perforated Casing in Complex Fracturing

2019 ◽  
Vol 944 ◽  
pp. 918-922
Author(s):  
Li Hong Han ◽  
Guang Xi Liu ◽  
Shang Yu Yang ◽  
Peng Wang
Keyword(s):  
Mechanical Properties ◽  
Oil And Gas ◽  
Physical Simulation ◽  
Element Model ◽  
Simulation Test ◽  
Gas Field ◽  
Gas Well ◽  
Fracturing Process ◽  
Oil And Gas Field ◽  
Unconventional Oil And Gas

For unconventional oil and gas well perforating technology, field complex fracturing process to carry out the casing perforation physical simulation test, determine the different perforating process corresponding to the aperture size morphology, based on this, according to the physical simulation test results, perforating casing finite element model is established, the analysis of stress concentration around the perforation under different construction conditions, determine the outer extrusion safety factor, for complex oil and gas field casing string design and provide technical support. Keywords: complex fracturing;perforation; casing; mechanical properties

Girth Weld Joints From Long Upset Pipe Ends for Improving Fatigue Strength of Offshore Oil and Gas Pipelines

2019 ◽  
Author(s):  
Israel Marines-Garcia ◽  
Aarón Aguilar ◽  
Ramón Aguilar ◽  
Mauricio Pelcastre ◽  
Philippe Darcis
Keyword(s):  
Mechanical Properties ◽  
Fatigue Strength ◽  
Structural Integrity ◽  
Oil And Gas ◽  
Numerical Comparison ◽  
Entire Line ◽  
Girth Welding ◽  
Production Stages ◽  
Offshore Oil And Gas ◽  
Girth Welds

Abstract For special high dynamic loading applications, the structural integrity of the girth welds shall withstand stress levels that might be on the limits of the permissible defect tolerances for current production welding standards for plain pipe ends. In addition, unexpected loading conditions might take the stress limits out of safe operation, which can compromise the entire line. As a solution, the cross section of the girth weld may be increased for ensuring the strength and fatigue resistance under any loading circumstances, including strain cycles of reeling installation technique. The employment of pipes with upset ends is an excellent option for those cases. To propose this option as an alternative to current offshore solution for a Major O&G company, Tenaris developed a long upset pipe end with enhanced fatigue life. The challenges of this work included the manufacturing of very long upset ends from a medium wall thickness pipe, very tight mechanical properties difference between pipe and upset material properties, and finally a welding qualification program. The improvement of the fatigue strength of this product was highly expected. In order to achieve all requirements, especial arrangements were performed on the upsetter machine for achieving the target upset geometry; which was previously obtained by a design of experiments technique. Then the heat treatment of the pipes was designed for obtaining the tight mechanical properties difference between pipe body and upset sections. The main outcomes of the whole development are described within this paper; which include key information of how to overcome issues that might arise during the development and production stages of upsetted line pipes. The upset ends undertake a cylindrical machining; this process provides the advantage of achieving tight dimensional tolerances in the high-low girth welding alignment. The fatigue endurance data after full scale reeling experimental test are included, as well as the numerical comparison between the strain fields of plain pipe and upset girth weld unions. The welding procedure qualified during this work is described. The results of the whole development were very satisfactory and, as expected, the fatigue strength of upset ends was higher than the plain pipe.

Mechanical Properties Characterization and Finite Element Analysis of Epoxy Grouts in Repairing Damaged Pipeline

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Lim Kar Sing ◽  
Nordin Yahaya ◽  
Alireza Valipour ◽  
Libriati Zardasti ◽  
Siti Nur Afifah Azraai ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Structural Integrity ◽  
Oil And Gas ◽  
Flexural Behavior ◽  
Fe Model ◽  
Element Analysis ◽  
Structural Repair ◽  
Repair Mechanisms ◽  
Infill Material

Oil and gas pipelines are subjected to various types of deterioration and damage over long service years. These damaged pipes often experience loss of strength and structural integrity. Repair mechanisms have been developed in restoring the loading capacity of damaged pipelines, and composite repair systems have become popular over the past few years. The mechanical properties of the putty/grout are critical to their potential application as infill materials in structural repair. In this paper, the compression, tensile, and flexural behavior of four epoxy grouts was investigated through laboratory tests. The stiffness of the grouts for compression, tensile, and flexural was found to be 6 GPa to 18 GPa, 4 GPa to 15 GPa, and 4 GPa to 12 GPa, respectively. The ultimate strength for all grouts was found from 62 MPa to 87 MPa, 18 MPa to 38 MPa, and 34 MPa to 62 MPa under compression, tensile, and flexural tests, respectively. The behavior of all the tested grouts is discussed. A finite element (FE) model simulating a composite-repaired pipe was developed and compared with past studies. The FE results show a good correlation with experimental test with margin of error less than 10%. By replacing the infill properties in FE model to mimic the used of different infill material for the repair, it was found that about 4–8% increment in burst pressure can be achieved. This signifies that the role of infill material is not only limited to transferring the load, but it also has the potential to increase overall performance of composite-repaired pipe.

Geomechanical Properties Estimation Utilizing Artificial Intelligence Prediction Tool

2021 ◽  
Author(s):  
Mohammed Alabbad ◽  
Mohammad Alqam ◽  
Hussain Aljeshi
Keyword(s):  
Mechanical Properties ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Significant Loss ◽  
Wellbore Stability ◽  
Rock Properties ◽  
Ann Model ◽  
Full Field ◽  
Geomechanical Properties ◽  
Rock Mechanical Properties

Abstract Drilling and fracturing are considered to be one of the major costs in the oil and gas industry. Cost may reach tens of millions of dollars and improper design may lead to significant loss of money and time. Reliable fracturing and drilling designs are governed with decent and representative rock mechanical properties. Such properties are measured mainly by analyzing multiple previously cored wells in the same formation. The nature of the conducted tests on the collected plugs are destructive and samples cannot be restored after performing the rock mechanical testing. This may disable further evaluation on the same plugs. This study aims to build an artificial neural network (ANN) model that is capable of predicting the main rock mechanical properties, such as Poisson's ratio and compressive strength from already available lab and field measurements. The log data will be combined together with preliminary lab rock properties to build a smart model capable of predicting advance rock mechanical properties. Hence, the model will provide initial rock mechanical properties that are estimated almost immediately and without undergoing costly and timely rock mechanical laboratory tests. The study will also give an advantage to performing preliminary estimates of such parameters without the need for destructive mechanical core testing. The ultimate goal is to draw a full field geomechanical mapping with this tool rather than having localized scattered data. The AI tool will be trained utilizing representative sets of rock mechanical data with multiple feed-forward backpropagation learning techniques. The study will help in localizing future well location and optimizing multi-stage fracturing designs. These produced data are needed for upstream applications such as wellbore stability, sanding tendency, hydraulic fracturing, and horizontal/multi-lateral drilling.

Finite Element Model Development for Structural Integrity of Shafts with Circumferential and Arbitrary Oriented Cracks

2015 ◽  
Vol 813-814 ◽  
pp. 905-909 ◽  
Author(s):  
R. Pramod ◽  
M.E. Shashi Kumar ◽  
S. Mohan Kumar
Keyword(s):  
Finite Element ◽  
Cylindrical Shell ◽  
Stress Intensity ◽  
Finite Element Model ◽  
Stress Intensity Factors ◽  
Structural Integrity ◽  
Accurate Determination ◽  
Bending Moment ◽  
Element Model ◽  
Intensity Factors

Tubular drive shafts are subjected to combined axial tension, torsional moment and bending moment. The structural integrity of the driveshaft is investigated by evaluating the change in strength, stiffness and the life of the driveshaft with the change in the crack length. A review of driveshaft failure analysis case histories identifies circumferential crack and arbitrarily oriented cracks to be critical. The singular stress field around a crack tip in a general shell structure is characterized by mixed mode membrane and bending stress intensity factors. Accurate determination of these stress intensity factors (less than 1%) are carried out by a subprogram named as 3MBSIF. The validation of Finite element model using ABAQUS and post processing subprogram 3MBSIF together is carried out using benchmarks, a set of standard test problems with known target solutions. Further SIFs are derived for cylindrical shell and the driveshaft under the action of bending moment. To quantify the change in the compliance of cylindrical shell and the driveshaft with change in crack lengths is studied by performing Modal Analysis. It was observed that the variation in frequency is higher for smaller crack angles.

Mechanical properties of FeAlSi powders prepared by mechanical alloying from different initial feedstock materials

2019 ◽  
Vol 107 (2) ◽  
pp. 207 ◽  
Author(s):  
Jaroslav Čech ◽  
Petr Haušild ◽  
Miroslav Karlík ◽  
Veronika Kadlecová ◽  
Jiří Čapek ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Alloying ◽  
Young’S Modulus ◽  
Milling Time ◽  
Young's Modulus ◽  
Element Model ◽  
X Ray Diffraction ◽  
X Ray ◽  
Powder Particles ◽  
Complete Homogenization

FeAl20Si20 (wt.%) powders prepared by mechanical alloying from different initial feedstock materials (Fe, Al, Si, FeAl27) were investigated in this study. Scanning electron microscopy, X-ray diffraction and nanoindentation techniques were used to analyze microstructure, phase composition and mechanical properties (hardness and Young’s modulus). Finite element model was developed to account for the decrease in measured values of mechanical properties of powder particles with increasing penetration depth caused by surrounding soft resin used for embedding powder particles. Progressive homogenization of the powders’ microstructure and an increase of hardness and Young’s modulus with milling time were observed and the time for complete homogenization was estimated.

scholarly journals Influence of Different Percentages of Binders on the Physico-Mechanical Properties of Rhizophora spp. Particleboard as Natural-Based Tissue-Equivalent Phantom for Radiation Dosimetry Applications

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1868
Author(s):  
Siti Hajar Zuber ◽  
Nurul Ab. Aziz Hashikin ◽  
Mohd Fahmi Mohd Yusof ◽  
Mohd Zahri Abdul Aziz ◽  
Rokiah Hashim
Keyword(s):  
Mechanical Properties ◽  
Radiation Dosimetry ◽  
Structural Integrity ◽  
Soy Flour ◽  
Lower Percentage ◽  
Internal Bonding ◽  
X Ray ◽  
Tissue Equivalent ◽  
Tissue Equivalent Phantom ◽  
Edx Analyses

Rhizophora spp. particleboard with the incorporation of lignin and soy flour as binders were fabricated and the influence of different percentages of lignin and soy flour (0%, 6% and 12%) on the physico-mechanical properties of the particleboard were studied. The samples were characterised by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), X-ray fluorescence (XRF) and internal bonding. The results stipulated that the addition of binders in the fabrication of the particleboard did not change the functional groups according to the FTIR spectrum. For XRD, addition of binders did not reveal any major transformation within the composites. SEM and EDX analyses for all percentages of binders added showed no apparent disparity; however, it is important to note that the incorporation of binders allows better bonding between the molecules. In XRF analysis, lower percentage of chlorine in the adhesive-bonded samples may be advantageous in maintaining the natural properties of the particleboard. In internal bonding, increased internal bond strength in samples with binders may indicate better structural integrity and physico-mechanical strength. In conclusion, the incorporation of lignin and soy flour as binders may potentially strengthen and fortify the particleboard, thus, can be a reliable phantom in radiation dosimetry applications.

scholarly journals Characterization of Mechanical Heterogeneity in Dissimilar Metal Welded Joints

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4145
Author(s):  
He Xue ◽  
Zheng Wang ◽  
Shuai Wang ◽  
Jinxuan He ◽  
Hongliang Yang
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Welded Joints ◽  
Structural Integrity ◽  
Material Interfaces ◽  
Mechanical Heterogeneity ◽  
Finite Element Software ◽  
Dissimilar Metal ◽  
Stress Changes

Dissimilar metal welded joints (DMWJs) possess significant localized mechanical heterogeneity. Using finite element software ABAQUS with the User-defined Material (UMAT) subroutine, this study proposed a constitutive equation that may be used to express the heterogeneous mechanical properties of the heat-affected and fusion zones at the interfaces in DMWJs. By eliminating sudden stress changes at the material interfaces, the proposed approach provides a more realistic and accurate characterization of the mechanical heterogeneity in the local regions of DMWJs than existing methods. As such, the proposed approach enables the structural integrity of DMWJs to be analyzed in greater detail.

scholarly journals Influence of the Heat Input on the Dendritic Solidification Structure and the Mechanical Properties of 2.25Cr-1Mo-0.25V Submerged-Arc Weld Metal

2021 ◽  
Author(s):  
Hannah Schönmaier ◽  
Ronny Krein ◽  
Martin Schmitz-Niederau ◽  
Ronald Schnitzer
Keyword(s):  
Mechanical Properties ◽  
Weld Metal ◽  
Heat Input ◽  
Stress Rupture ◽  
Pressure Vessels ◽  
Rupture Time ◽  
Solidification Structure ◽  
Welding Parameters ◽  
Austenite Grain Size ◽  
Submerged Arc

AbstractThe alloy 2.25Cr-1Mo-0.25V is commonly used for heavy wall pressure vessels in the petrochemical industry, such as hydrogen reactors. As these reactors are operated at elevated temperatures and high pressures, the 2.25Cr-1Mo-0.25V welding consumables require a beneficial combination of strength and toughness as well as enhanced creep properties. The mechanical properties are known to be influenced by several welding parameters. This study deals with the influence of the heat input during submerged-arc welding (SAW) on the solidification structure and mechanical properties of 2.25Cr-1Mo-0.25V multilayer metal. The heat input was found to increase the primary and secondary dendrite spacing as well as the bainitic and prior austenite grain size of the weld metal. Furthermore, it was determined that a higher heat input during SAW causes an increase in the stress rupture time and a decrease in Charpy impact energy. This is assumed to be linked to a lower number of weld layers, and therefore, a decreased amount of fine grained reheated zone if the multilayer weld metal is fabricated with higher heat input. In contrast to the stress rupture time and the toughness, the weld metal’s strength, ductility and macro-hardness remain nearly unaffected by changes of the heat input.

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