Fig 9 - uploaded by Obeid Obeid
Content may be subject to copyright.
Schematic sketch of predicted temperature positions in Case A, Case B and Case C along the axial direction (mm).
Source publication
![Thermo-mechanical properties of C-Mn [4].](profile/Obeid-Obeid/publication/320578811/figure/tbl1/AS:779119532994560@1562767980078/Thermo-mechanical-properties-of-C-Mn-4_Q320.jpg)
This paper investigates numerical thermal fields and residual stresses induced by single-pass weld overlay (lap-weld) and girth welding (butt-weld) in lined pipe using Tungsten Inert Gas (TIG) welding. A distributed power density of the moving heat source based on Goldak’s ellipsoid heat flux distribution is used in a Finite Element (FE) simulation...
Context in source publication
Context 1
... the present study, the thermal history profiles are obtained at six locations along the axial direction for Case A, Case B and Case C where points T1, T2 and T3 are placed upon the inner surface while points T4, T5 and T6 are mounted on the outer surface as shown schematically in Fig. 9. ...
Similar publications
In the present experimentation, a 10mm thick austenitic stainless steel plate type 304L is welded using single V-joint configuration and approaching the joint from one side. Back purging has been employed to protect the rear side of the root pass weld metal against oxidation. The root pass has been deposited by gas tungsten arc welding (GTAW) proce...
The purpose of this study was to evaluate the temperature fluctuation induced by electromagnetic stirring (EMS) and to investigate the influence of temperature fluctuation on the appearance and microstructure of the stainless steel welds. CF8A and 308L were used for the base metal and weld metal, respectively. Bead-on-plate welding (BOP) was conduc...
This study compared the effect of the interaction time of periodic water clusters on the surface integrity of AISI 304 tungsten inert gas (TIG) welded joints at different excitation frequencies, as the effect of the technological parameters of pulsating water jet (PWJ) on the mechanical properties of TIG welded joints are under-researched. The TIG...
Defects, such as cracks, typically occur in the spinning process of ternary catalyst shells. This study investigates the optimization of spinning process parameters to prevent such defects. An orthogonal simulation is performed using a finite element model of the spinning process of a ternary catalyst shell. The simulation results are verified by p...
Motivated by increasing productivity and cost-effectiveness, the feasibility of Keyhole Tungsten Inert Gas (K-TIG) welding for joining SAF2205/AISI316L dissimilar materials was presented. Single pass autogenous welding was achieved on 5.6 mm thick plates at a speed of 35 cm/min without using any filler materials and edge preparation. In-depth inves...
Citations
... Goldak's ellipsoidal heat source model has been extensively applied in numerical simulations to predict residual stresses and distortions caused by transient thermal fields during welding. Studies have shown that these simulations provide results in good agreement with experimental validations [10]. ...
The present work evaluates residual stress and distortion in Thermo-Mechanical Control Process (TMCP) grade EH-36 steel plates subjected to hybrid Gas Tungsten Arc Welding (GTAW) and Shielded Metal Arc Welding (SMAW) processes Specimens measuring 650 × 170 mm with a thickness of 12 mm were utilized. Finite Element Method (FEM) analysis was employed to model residual stress and distortion, a critical step in optimizing the manufacturing process of mechanical structures and parts in shipbuilding. The FE model was developed using ANSYS software incorporating a heat source model with a user-defined subroutine to represent an ellipsoidal moving weld torch with front and rear power density distribution. Heat losses due to radiation and convection were accounted for, while mechanical boundary conditions were applied to restrict rotation and displacement but allow material deformation. Thermal analysis demonstrated close agreement between experimental thermocouple data and numerical simulations, with a temperature deviation of only 5%. Residual stress analysis using X-Ray Diffraction (XRD) revealed that ultrasonic stress relief reduced the maximum residual stress from an average of 193.4 MPa to 39.1 MPa Distortion analysis showed that the maximum FEM deformation was 0.2873 mm, with a 12% deviation from coordinate measuring machine (CMM) results, while the minimum FEM deformation was 0.031922 mm, differing by 3%. The larger deviation occurred in areas with peak distortion, attributed to variations in mechanical restraint positioning, which significantly influence material deformation during cooling.
... The experimental methods need proper welding equipment with proper voltage, current, and necessary safety, along with sufficient time to execute the experiments. In contrast to the experimental procedure, simulation developed upon the finite element (FE) technique performed in MSC Marc or any numerical simulation environment is well-executed and tested several times for faultless or precise temperature distribution; the welding residual stresses in welding mechanization are also economically efficient [10]. ...
Controlling defects such as deformation in the weld joint and the residual or superfluous stresses due to tungsten inert gas (TIG) welding or arc welding is a major concern for many industries like aeronautical, automobiles, nuclear or atomic power plants, crude oil or fossil fuel industries where pipes are in use and circumferential welding is done. Arc welding is a metal joining process, and TIG welding is applied to many industrial sectors that require high-quality welding. Simulation has been done on single-pass TIG welding on the Flange pipe of SS316 to evaluate transient temperature, residual stresses, and distortion. First, a 3D model is developed and assembled in SolidWorks. Second, in an MSC Patran, preprocessing of the FE model is done. Finally, in MSC Marc, thermal and mechanical simulation is performed. Based on this simulation, the accuracy of welding of the flange–butt joint made of SS316 is validated. In this study, the information regarding simulation of temperature dispensation and residual or superfluous stresses is done on the flange–butt joint, and it found the stresses are compressive at the weld bead area, and along the transverse direction, stresses changed to the tensile. The experimental data show that the steep curve at 0.00 mm represents a maximum temperature near the weld path at approximately 2,352°C, and the slant curve shows the far away points from the weld path. Comparing it with FE analysis, the maximum temperature attained was around 2,539°C. An approximate deviation of 7.365% was observed. The results of the study will provide experimental and simulation analyses for the welding of pipes of stainless steel for the transportation of oil and gases in the petroleum industries.
... The source efficiency coefficient is 0.7 [13,24,25]. The temperature-dependent properties of the 304 stainless steel [27] are used in the simulation. The birth-death element method was employed to simulate the layer-by-layer deposition of the WAAM process. ...
Finite element (FE) coupled thermal-mechanical analysis is widely used to predict the deformation and residual stress of wire arc additive manufacturing (WAAM) parts. In this study, an innovative single-layer multi-bead profile geometric modeling method through the isosceles trapezoid function is proposed to build the FE model of the WAAM process. Firstly, a straight-line model for overlapping beads based on the parabola function was established to calculate the optimal center distance. Then, the isosceles trapezoid-based profile was employed to replace the parabola profiles of the parabola-based overlapping model to establish an innovative isosceles trapezoid-based multi-bead overlapping geometric model. The rationality of the isosceles trapezoid-based overlapping model was confirmed by comparing the geometric deviation and the heat dissipation performance index of the two overlapping models. In addition, the FE-coupled thermal-mechanical analysis, as well as a comparative experiment of the single-layer eight-bead deposition process show that the simulation results of the above two models agree with the experimental results. At the same time, the proposed isosceles trapezoid-based overlapping models are all straight-line profiles, which can be divided into high-quality FE elements. It can improve the modeling efficiency and shorten the simulation calculation time. The innovative modeling method proposed in this study can provide an efficient and high-precision geometric modeling method for WAAM part FE coupled thermal-mechanical analysis.
... Karlsson et al. [1] utilized the finite element method to simulate the welding process of carbon steel tube SIS2172 (Swedish standard steel), obtaining insights into the temperature and stress distribution during welding. Obeid et al. [2] employed a moving heat source model, grounded in Goldak's double ellipsoid heat flow distribution, and took into account convective and radiative heat transfer boundaries to analyze thermal isotherms and residual stress distributions in surfacing layers and girth weld lining pipes. Jiang Shengfei et al. [3] applied life-and-death unit technology in simulating the welding process of V-groove bimetal composite pipes. ...
... The range of 6-8% deviation was observed with predicting results. Obeid et al. [8] modeled a 3D structure using FE ABAQUS code to predict thermal cycles and stresses induced in welding process. The FE result indicated clearly that angle (circumferential direction) have fewer impact on results. ...
This research paper aims at predict the thermal and residual stresses in dissimilar welds of AA5083 and AA6082 using ANSYS®. The combination of dissimilar components are widely used where high corrosion resistance and good mechanical properties required. Thermo-mechanical properties were predicted by developing 3-Dimensional Goldak ellipsoidal model. Suitable boundary conditions were applied during simulation in order to predict accurate results in the welded structures. Element types, SOLID 70 for thermal and SOLID 185 for structural analyses were considered. Convective heat transfer co-efficient and radiation boundary conditions were considered during thermal analysis. The FE results obtained from these thermal model were taken into account to predict the stress formation along welding and transverse direction. For this, static structural analysis has been performed. The stress formation in TIG welding process were predicted at different zones of welded structures. In order to validate these stress values at different locations, XRD technique is used to measure the stress distribution experimentally. Peak temperatures were predicted during the course of process when the source model is moving along the welding direction. The predicted residual stresses are validated and which are in good agreement with measured values and the measured data values are within yield limits only.
... In contrast to quarter circumference Concept for root welding pass, numerous researchers [3,6,9,[40][41][42][43][44][45][46][47][48] conducted a full circumferential welding for the RP. Some studies [6,9,42,44,45,48] adopted certain mechanical boundary condition, but did not clarify if weld tacks had been adopted as a tool to control the welding distortion. ...
... In contrast to quarter circumference Concept for root welding pass, numerous researchers [3,6,9,[40][41][42][43][44][45][46][47][48] conducted a full circumferential welding for the RP. Some studies [6,9,42,44,45,48] adopted certain mechanical boundary condition, but did not clarify if weld tacks had been adopted as a tool to control the welding distortion. In a few Table 1 The chemical compositions of pipe specimen and weld filler material (Wt%). ...
... Concept3 (Fig. 8b): Proposed in the present study, RP by the order of RPI, RPII, RPIII and RP IV. Concept4 (Fig. 8c): The idea of RP by full circumferential welding was adopted by several researchers [3,40,[42][43][44]48], and was develop to a novel Concept proposed in the present study. The WTs were covered by one full circumference RP. ...
A three-dimensional (3D) finite element (FE) model based on thermal-elastic-plastic approach in SYSWELD® was employed to investigate the effects of welding sequences on induced residual stresses and radial distortion in AISI 316L stainless steel welded pipes. To mesh the model, the HYPERMESH® processor was utilized and the model was then exported to SYSWELD® for further thermo-mechanical analysis. The Goldak's double ellipsoidal moving heat source model was employed in SYSWELD® to obtain the volumetric heat flux density in the Gas Metal Arc Welding (GMAW) simulation process. A neural-network program was suitably trained and used to predict the parameters of Goldak's model. The obtained numerical models using predicted Goldak’s parameters were then successfully validated by experimental results in terms of size of welding pool and the temperature distribution. Four different welding sequences (concepts) were investigated and compared: three quarters and one full circumferential welding. These welding sequences were anticipated to create the least residual stress and distortion in pipe welding. The results demonstrate that the welding sequences significantly influence induced residual stresses and distortions in magnitude and in distribution. For the full circumferential welding concept, which was proposed in this study, the residual stresses and distortion present more uniform distribution along the circumferential direction than those in quarter welding sequences. The magnitude of welding distortion was also significantly lower in the full circumferential concept when compared to the quarter welding concepts. The FE results of residual stresses in the full circumferential welding sequences were accurately validated by experimental tests.
... The FE Analysis is the most effective numerical tool for predicting temperature distribution, residual stresses along with thermal distortions in welded joints. Many authors have developed the FEA models for different materials and welded joints [10][11][12][13][14]. The FEA software packages such as ANSYS, SYSWELD, WELDSIM and ABAQUS are used by various researchers for analyzing the weldments. ...
... nλ 2dsinθ (12) Since surface strains can only be measured using XRD technique, the residual stress σ_∅ values are calculated separately using the following Eq. 13. ...
The finite element analysis is the most effective numerical tool for predicting temperature distribution, residual stresses along with thermal distortions in welded joints. In this paper, the temperature gradients and also thermally induced stresses were predicted numerically by performing coupled thermo-mechanical analyses. The elemental birth and death techniques were considered for modeling the filler element. The suitable boundary conditions such as heat transfer coefficient as well as radiation considered for predicting accurate results. Thermally induced residual stresses in the Inconel 718 and AISI 316 dissimilar joints were measured experimentally by using X-ray diffraction technique. Five different points were taken to measure the stresses in order to validate the results obtained from FE results. The peak temperatures were predicted at the HAZ of Inconel 718 than the HAZ of AISI 316. Thermal stresses which were predicted in compressive nature at weld zone due to improper thermal cooling cycles. The predicted residual stresses in this dissimilar weldments with the yield limits and self-balanced and these stresses were in good agreement with experimentally obtained stresses.
... For instance FEM is commonly used to investigate the residual stresses created during GTAW pipe welding. Obeid et al. [41] used ABAQUS to simulate orbital GTAW on 6 mm AISI 304 pipe. Further Ravisankar et al. used another program, SYSWELD, to simulate orbital pipe welding on 2.5 mm thick AISI 304 stainless steel [42]. ...
... Note in the origional study Goldak et al. [47] used an efficiency of 95% but this is omitted as it is quite out of step with modern experimental measurements and simulations. [26] 0.75 Alloy 718 Karpagaraj et al. [11] 0.50 CP Titanium Malik et al. [61] 0.80 AH36 Steel Obeid et al. [41] 0.70 AISI 304 Ravisankar et al. [42] 0.80 AISI 304 ...
... Broadly, these can be split into commercial software, open-source non-profit software and complete custom software created from scratch. Much of the commercial software mentioned thus far is FEM based such as ABAQUS [41,43], SYSWELD [42] and MSC Marc [25,26]. However there are two prominent FVM software packages ANSYS Fluent and COMSOL. ...
This thesis presents a novel multiphysics solver, named gtawFoam, for Gas Tungsten Arc Welding (GTAW) that is applied to simulate orbital GTAW on ultra-thin-walled titanium tubing. In this thesis, ultra-thin-walled tubing refers to tubing where the wall thicknesses are less than 500 . Orbital welding of tubing with this wall thickness requires both a sufficient heat input to weld the tubing and an internal buttressing gas flow to ensure the tube retains its geometrical integrity. The specific use case is for the commercially pure grade 2 titanium tubing used in the ATLAS ITk cooling system which is 2.275 mm outer diameter and 300 wall thickness at the weld. The solver is created using the open source computational fluid dynamics library OpenFOAM and each component of the solver is benchmarked against an appropriate case. With the solver established, it is used to simulate a series of welding procedures that were performed experimentally on the aforementioned titanium tubing. Both the experimental and simulation results show a `goldilocks' region where the weld heat input and inner buttressing gas flow are moderated to a level where a fully penetrating weld is created but the geometric integrity of the tube is not compromised. gtawFoam is then used to simulate hypothetical tubing with larger and smaller wall thicknesses between 250 and 350 . The results suggest that the required buttressing gas pressure once achieved is relatively transferable between wall thickness changes but applying enough heat so as to achieve full penetration is critical. These results are then used to predict effective welding procedures for this hypothetical tubing. gtawFoam is subsequently applied to the welding of turbine blades. This includes the addition of multiple layers of filler metal to mimic additive manufacturing.
... 12(a) and (b). The elliptical shape of temperature distribution can be observed on the outer surface of the pipe specimen for both welding passes which are in agreement with previous researches [70,71]. variance in peak temperatures between experimental and FE simulation results were 3.06% and 3.75% at 15 mm and 25 mm locations, respectively. ...
The double-ellipsoidal heat source concept, established by Goldak, has been extensively employed to represent the energy distribution in a broad range of arc welding simulation processes. However, the Goldak’s parameters need to be exactly and efficiently defined for accurate arc welding simulation. In this study, a novel procedure was proposed to accurately predict the Goldak’s parameters in Gas Tungsten Arc (GTA) Welding simulation. A developed three dimensional (3D) Finite element (FE) analysis was performed to generate thirty sets of normalized input (welding pool characteristics) and outputs (Goldak’s parameters). The relevance between Goldak’s parameters and welding pool characteristics were established using two regression models and Artificial Neural Network (ANN) computing systems. Linear and quadratic regression models and ANN were compared for evaluation of accuracy of the parameters. Analysis of the results indicated that ANN slightly transcends both regression models, even though the regression models and ANN were able to suitably predict Goldak’s parameters for welding simulation. Hence, Goldak’s parameters for the welding numerical model were estimated and employed from the ANN model. 3D FE analysis based on thermal-elastic-plastic model using predicted Goldak’s parameters were then conducted and validated by the experimental tests in terms of the size of welding pool, temperature distribution and induced residual stress. In the proposed procedure, the data set in training process was obtained using an efficient FE model analysis, which eliminates the cost and time associated with plenty of experimental tests.
... An increase in the outer diameter of the cylinder increases the bending in welded cylinders [12]. Experimental investigations on longitudinally welded pipes revealed the cracks initiated on the I/S of the cylinder, where the residual stresses are tensile and maximum [13]. An investigation on welded line pipes reported that the residual axial stresses initiate fatigue cracks at the weld root [14]. ...
Welded cylinder structures such as pressure vessels and pipes have found its application in power stations. They experience high temperature and pressure during the operation. As welding induces residual stresses, it is vital to study the stress distribution in predicting their service lives. In the present work, a sequentially coupled thermal structural analysis is carried to study the thermal field distribution and subsequent residual stresses during welding. Finite element (FE) model of gas tungsten arc welding (GTAW) process is developed to produce circumferential and longitudinal butt weld joints of AH 36 (low carbon steel) cylinder components. Welding of cylinders is analyzed by changing their outer diameters. Effect of cylinder outer diameter on residual stresses is studied. The weld induced hoop and axial stresses are evaluated on both inner surface (I/S) and outer surface (O/S) of the cylinder. The magnitude of hoop and axial stresses in longitudinal butt weld joints are 45% and 95% higher than circumferential butt weld joints. By comparing the results, longitudinal butt weld joints are not desirable for fabricating cylinder components. The analysis model is validated with experimental measurements.
