scholarly journals Finite element modelling of multi-pass fusion welding with application to complex geometries

2007 ◽  
Vol 221 (4) ◽  
pp. 225-234 ◽  
Author(s):  
W Jiang ◽  
K Yahiaoui
Keyword(s):  
Residual Stress ◽  
Three Dimensional ◽  
Welding Process ◽  
Industrial Applications ◽  
Fusion Welding ◽  
Modelling Technique ◽  
Welding Parameters ◽  
Complex Geometries ◽  
Stress Distributions ◽  
Element Removal

The current paper presents recently completed work in the development of advanced multi-pass weld modelling procedures, with the ultimate objective of predicting weld residual stress distributions in thick-walled complex geometries. The modelling technique was first developed using simple three-dimensional geometries, for which experimental data was available for validation purposes. All the non-linearities associated with welding, including geometry, material, and boundary non-linearities, as well as heat source movement were taken into account. The element removal/reactivate technique was employed to simulate the deposition of filler material. Combined with a newly developed meshing technique, the model was then applied to predict residual stress distributions for a relatively thick stainless steel piping branch junction. Finally, a parametric study was conducted to assess the effects of various manufacture-related welding parameters on the final residual stress fields. The interpass temperature and cooling rate were found to be the two most sensitive parameters affecting resultant residual stresses. The residual stress profiles can be optimized relatively easily by adjusting these parameters. This research demonstrated that the developed modelling technique has potential in multi-pass welding process optimization and wide industrial applications including weld repairs.

Numerical Simulations of Friction Stir Welding Process and Subsequent Post Weld Cold Rolling Process

2009 ◽  
Vol 419-420 ◽  
pp. 433-436 ◽  
Author(s):  
Yu Jie Sun ◽  
Yong Zang ◽  
Qing Yu Shi
Keyword(s):  
Residual Stress ◽  
Friction Stir Welding ◽  
Three Dimensional ◽  
Welding Process ◽  
Rolling Process ◽  
Mechanical Analysis ◽  
Fusion Welding ◽  
Work Piece ◽  
Friction Stir ◽  
Longitudinal Residual Stress

A sequential coupled three-dimensional thermo-mechanical analysis was conducted first to simulate friction stir welding (FSW) of aluminum alloy. In thermal analysis, the model included adaptive heat source, contact heat transfer both between work piece and clamps and between work piece and backing board etc; in the mechanical analysis, the model involved contact interaction both between work piece and clamps and between work piece and backing board, mechanical load of tool etc. The simulation results indicate that the longitudinal residual stress is unsymmetrical about weld centerline; the magnitude of longitudinal residual stress for FSW process is lower than that for fusion welding process. Based on simulated results of FSW process, a three-dimensional elastic-plastic analysis was then carried out to simulate rolling process, the simulation result show that rolling process not only causes a marked reduction in the longitudinal tensile residual but also reverse the sign of the longitudinal residual stress.

scholarly journals Finite Element Prediction of Residual Stress Distributions in a Multipass Welded Piping Branch Junction

2006 ◽  
Author(s):  
Wei Jiang ◽  
Kadda Yahiaoui
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Welding Process ◽  
Pressure Vessels ◽  
Welding Residual Stress ◽  
Stress Distributions ◽  
Multipass Welding ◽  
Hexahedral Elements ◽  
Element Removal

Piping branch junctions and nozzle attachments to main pressure vessels are common engineering components used in the power, oil and gas, and shipbuilding industries amongst others. These components are usually fabricated by multipass welding. The latter process is known to induce residual stresses at the fabrication stage which can have severe adverse effects on the in-service behavior of such critical components. It is thus desirable if the distributions of residual stresses can be predicted well in advance of welding execution. This paper presents a comprehensive study of three dimensional residual stress distributions in a stainless steel tee branch junction during a multipass welding process. A full 3D thermo-mechanical finite element model has been developed for this purpose. A newly developed meshing technique has been used to model the complex intersection areas of the welded junction with all hexahedral elements. Element removal/reactivate technique has been employed to simulate the deposition of filler material. Material, geometry and boundary nonlinearities associated with welding were all taken into account. The analysis results are presented in the form of stress distributions circumferentially along the weldline on both run and branch pipes as well as at the run and branch cross sections. In general, this computational model is capable of predicting 3D through thickness welding residual stress, which can be valuable for structural integrity assessments of complex welded geometries.

scholarly journals Finite Element Prediction of Residual Stress Distributions in a Multipass Welded Piping Branch Junction

2006 ◽  
Vol 129 (4) ◽  
pp. 601-608 ◽  
Author(s):  
Wei Jiang ◽  
Kadda Yahiaoui
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Three Dimensional ◽  
Pressure Vessels ◽  
Welding Residual Stress ◽  
Stress Distributions ◽  
Multipass Welding ◽  
Hexahedral Elements ◽  
Element Removal

Piping branch junctions and nozzle attachments to main pressure vessels are common engineering components used in the power, oil and gas, and shipbuilding industries amongst others. These components are usually fabricated by multipass welding. The latter process is known to induce residual stresses at the fabrication stage, which can have severe adverse effects on the in-service behavior of such critical components. It is thus desirable if the distributions of residual stresses can be predicted well in advance of welding execution. This paper presents a comprehensive study of three dimensional residual stress distributions in a stainless steel tee branch junction during a multipass welding process. A full three dimensional thermomechanical finite element model has been developed for this purpose. A newly developed meshing technique has been used to model the complex intersection areas of the welded junction with all hexahedral elements. Element removal/reactivate technique has been employed to simulate the deposition of filler material. Material, geometry, and boundary nonlinearities associated with welding were all taken into account. The analysis results are presented in the form of stress distributions circumferentially along the weld line on both run and branch pipes as well as at the run and branch cross sections. In general, this computational model is capable of predicting three dimensional through-thickness welding residual stress, which can be valuable for structural integrity assessments of complex welded geometries.

scholarly journals Finite Element Predictions of Temperature Distributions in a Multipass Welded Piping Branch Junction

2005 ◽  
Vol 127 (1) ◽  
pp. 7-12 ◽  
Author(s):  
Wei Jiang ◽  
Kadda Yahiaoui ◽  
Frank R. Hall
Keyword(s):  
Residual Stress ◽  
Three Dimensional ◽  
Welding Process ◽  
Stress Distributions ◽  
Temperature Dependent ◽  
Material Microstructure ◽  
Temperature Distributions ◽  
Control Schemes ◽  
Complex Temperature ◽  
Walled Cylinder

This contribution deals with the complex temperature profiles that are generated by the welding process in the intersection region of thick walled, cylinder-cylinder junctions. These affect material microstructure, mechanical properties and residual stresses. Knowledge of the thermal history and temperature distributions are thus critical in developing control schemes for acceptable residual stress distributions to improve in-service component behavior. A comprehensive study of three-dimensional temperature distributions in a stainless steel tee branch junction during a multipass welding process is presented. A newly developed partitioning technique has been used to mesh the complex intersection areas of the welded junction. Various phenomena associated with welding, such as temperature dependent material properties, heat loss by convection and latent heat have been taken into consideration. The temperature distribution at various times after deposition of certain passes and the thermal cycles at various locations are reported. The results obtained in this study will be used for on-going and future analysis of residual stress distributions. The meshing technique and modeling method can also be applied to other curved, multipass welds in complex structures.

scholarly journals Optimization on Spot Weld Parameters in Resistance Spot Welding Process on AISI 304

2021 ◽  
Vol 11 (3) ◽  
pp. 181-185
Author(s):  
Amit Hazari ◽  
Rith Saha ◽  
Bidisha Ghosh ◽  
Debraj Sengupta ◽  
Sayan Sarkar ◽  
...  
Keyword(s):  
Resistance Spot Welding ◽  
Spot Welding ◽  
Welding Process ◽  
Welding Current ◽  
Electrical Current ◽  
Industrial Applications ◽  
Spot Weld ◽  
Welding Parameters ◽  
Resistance Spot ◽  
Weld Time

The spot welding procedure is used in a variety of industrial applications. The most critical elements influencing welding quality, productivity, and cost are the spot welding parameters. This research examines the effect of welding factors such as welding current and welding time on the strength of various welding joint designs. Resistance spot welding (RSW) is used in the automotive industry for manufacturing. This research focused on the optimization of process parameters for resistance spot welding (RSW), as well as the tensile testing and spot weld diameter. The goals of this analysis are to comprehend the physics of the process and to demonstrate the effect of electrical current, weld time, and material type on the resistance spot welding process.

Comparison between Modelled Influence of GMAW Parameters and Corresponding Mechanical Properties of Group 1 and 2 According to ISO/TR 15608 Steel T Joints

2021 ◽  
Vol 890 ◽  
pp. 17-24
Author(s):  
Aurel Valentin Bîrdeanu ◽  
Alin Constantin Murariu ◽  
Horia Florin Daşcău ◽  
Iuliana Duma
Keyword(s):  
Process Parameters ◽  
High Performance ◽  
Hsla Steel ◽  
Welding Process ◽  
High Strength ◽  
Industrial Applications ◽  
Steel Plates ◽  
Experimental Program ◽  
Welding Parameters ◽  
T Joints

Reproducibility in respect to welded structures realization is one of the main requirements for a wide variety of industrial applications. One of the international tendencies regarding the use of the steel is the replacing, in critical areas, of structural steels with high performance steel, e.g. with HSLA steels. The paper presents the results of a factorial designed experimental program focused on determining mathematical correlations between the GMAW process parameters for T joints of 4mm thick steel plates of structural (S235JR+AR according to SR EN 10025-2) and hot-rolled, high-strength low-alloy (HSLA) steel plates (S420MC according to EN 10025-4), respectively. A comparison between the obtained mathematical correlations that connect the welding parameters and the main mechanical characteristics is presented. The correlations can be used for applying the optimal combination of welding process parameters for realizing the T-joints of welded products.

scholarly journals Study on Residual Stress of Welded Hoop Structure

2020 ◽  
Vol 10 (8) ◽  
pp. 2838
Author(s):  
Wenbo Ma ◽  
Heng Zhang ◽  
Wei Zhu ◽  
Fu Xu ◽  
Caiqian Yang
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Welding Speed ◽  
Weld Seam ◽  
Outer Cylinder ◽  
Three Dimensional ◽  
Welding Residual Stress ◽  
Welding Parameters ◽  
Forming Process ◽  
Maximum Residual Stress

Residual stress is inevitable during welding, which will greatly affect the reliability of the structure. The purpose of this paper was to study the residual stress of the hoop structure caused by the cooling shrinkage of the weld when the outer cylinder was wrapped and welded under the condition of the existing inner cylinder. In this paper, the “method of killing activating elements” of ANSYS was used to simulate the three-dimensional finite element of the hoop structure. In the case of applying interlayer friction, the welding-forming process and welding circumferential residual stress of the hoop structure were analyzed. The blind hole method was used to test the residual stress distribution of the hoop structure, and the test results were compared with the finite element simulation results to verify the reliability of the simulation calculation method and the reliability of the calculation results. Then, the influence factors of the maximum welding residual stress of the hoop structure were studied. The results show that the maximum residual stress of the outer plate surface of the hoop structure decreases with the increase of the welding energy, the thickness of the laminate, the width of the weld seam, the welding speed, and the radius of the container. Based on the results of numerical simulation, the ternary first-order equations of the maximum residual stress of the hoop structure with respect to the welding speed, the thickness of the laminate, and the width of the weld seam were established. Then, the optimal welding parameters were obtained by optimizing the equations, which provided an important basis for the safe use and optimal design of the welding hoop structure.

FE Predictions of Temperature Distributions in a Multipass Welded Piping Branch Junction

2004 ◽  
Author(s):  
Wei Jiang ◽  
Kadda Yahiaoui ◽  
Chang J. Wang ◽  
Frank R. Hall ◽  
Tahar Laoui
Keyword(s):  
Residual Stress ◽  
Welding Process ◽  
Stress Distributions ◽  
Temperature Dependent ◽  
Material Microstructure ◽  
Temperature Distributions ◽  
Control Schemes ◽  
Complex Temperature ◽  
Walled Cylinder ◽  
Comprehensive Study

This contribution deals with the complex temperature profiles that are generated by the welding process in the intersection region of thick walled, cylinder-cylinder junctions. These affect material microstructure, mechanical properties and residual stresses. Knowledge of the thermal history and temperature distributions are thus critical in developing control schemes for acceptable residual stress distributions to improve in-service component behavior. A comprehensive study of 3D temperature distributions in a stainless steel tee branch junction during a multipass welding process is presented. A newly developed partitioning technique has been used to mesh the complex intersection areas of the welded junction. Various phenomena associated with welding, such as temperature dependent material properties, heat loss by convection and latent heat have been taken into consideration. The temperature distribution at various times after deposition of certain passes and the thermal cycles at various locations are reported. The results obtained in this study will be used for on-going and future analysis of residual stress distributions. The meshing technique and modeling method can also be applied to other curved, multipass welds in complex structures.

Residual Stress Prediction for Non-Axisymmetric Vessel Penetration Welds

2008 ◽  
Author(s):  
Kazuo Ogawa ◽  
Nobuyoshi Yanagida ◽  
Koichi Saito
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Three Dimensional ◽  
Measurement Data ◽  
Fe Model ◽  
Stress Distributions ◽  
Dimensional Finite Element ◽  
Stress Prediction ◽  
Three Dimensional Finite Element ◽  
Good Agreement

Residual stress distribution in an oblique nozzle jointed to a vessel with J-groove welds was analyzed using a three-dimensional finite element method. All welding passes were considered in a 180-degree finite element (FE) model with symmetry. Temperature and stress were modeled for simultaneous bead laying. To determine residual stress distributions at the welds experimentally, a mock-up specimen was manufactured. The analytical results show good agreement with the experimental measurement data, indicating that FE modeling is valid.

Influence of Tool Rotational Speed on the Mechanical Properties of Friction Stir Welded Al-Cu-Li Alloy

2016 ◽  
Vol 857 ◽  
pp. 228-231
Author(s):  
Ho Sung Lee ◽  
Ye Rim Lee ◽  
Kyung Ju Min
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Space Shuttle ◽  
Welding Process ◽  
High Strength ◽  
Fusion Welding ◽  
Welding Parameters ◽  
Friction Stir ◽  
Mechanical And Microstructural Properties ◽  
Tool Rotation

Aluminum-Lithium alloys have been found to exhibit superior mechanical properties as compared to the conventional aerospace aluminum alloys in terms of high strength, high modulus, low density, good corrosion resistance and fracture toughness at cryogenic temperatures. Even though they do not form low-melting eutectics during fusion welding, there are still problems like porosity, solidification cracking, and loss of lithium. This is why solid state friction stir welding is important in this alloy. It is known that using Al-Cu-Li alloy and friction stir welding to super lightweight external tank for space shuttle, significant weight reduction has been achieved. The objective of this paper is to investigate the effect of friction stir tool rotation speed on mechanical and microstructural properties of Al-Cu-Li alloy. The plates were joined with friction stir welding process using different tool rotation speeds (300-800 rpm) and welding speeds (120-420 mm/min), which are the two prime welding parameters in this process.

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