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.

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.

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.

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.

Effect of Welding Sequence on the Residual Stress Distribution in a Stiffened Plate

2016 ◽  
Author(s):  
Bai-Qiao Chen ◽  
C. Guedes Soares
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Lower Layer ◽  
Plate Thickness ◽  
Three Dimensional ◽  
Welding Process ◽  
Residual Stress Distribution ◽  
Steel Plates ◽  
Tension Zone ◽  
Welding Sequence

This work investigates the temperature distribution, deformation and residual stress in steel plates as a result of different sequences of welding. The single-pass gas tungsten arc welding process is simulated by a three dimensional nonlinear thermo-elasto-plastic approach. It is observed that the distribution of residual stress varies through the direction of plate thickness. It is concluded that the welding sequence affects not only the welding deformation but also the residual stress mainly in the lower layer of the plates. An in-depth discussion on the pattern of residual stress distribution is presented, especially on the width of the tension zone. Smaller residual tension zone and slightly lower compressive stress are found in thicker plate.

Mathematical Model for Multi-Component Forces and Torque Determination in Friction Stir Welding

2011 ◽  
Vol 230-232 ◽  
pp. 1255-1259
Author(s):  
T. Khairuddin Jauhari ◽  
I.P. Almanar ◽  
Hussain Zuhailawati
Keyword(s):  
Mathematical Model ◽  
Friction Stir Welding ◽  
Early Stage ◽  
Three Dimensional ◽  
Welding Process ◽  
Temperature Dependent ◽  
Metallic Material ◽  
Friction Stir ◽  
Work Material ◽  
Force Components

Major works concentrated on the energy conversion from mechanical friction work to heat; emphasized on the immediate contact surface of work material and rotating welding tool but with no in-depth analytical study to relate the loads that are transferred to the work material and the welding fixture especially at early stage of heat generation. In this work, a mathematical model is developed to predict three-dimensional force components and axial torque of the rotating tool based on contact mechanic principle in relation to Al6061 temperature-dependent material properties. The model shows the ability to be possibly adapted for different metallic material and physical properties. It suggests the exerted torque and loads calculation endured by work material involving friction and shear mechanism of two static-dynamic contacting surface; rotating rotational tool and the fixed work material, to be used as one of the option for optimization of the welding process such as to determine the ratio of slip, non-slip contact condition through comparisons of experimental and computer simulation on the Friction Stir Welding process.

A Three-Dimensional Finite Element Evaluation of a Destructive Experimental Method for Determining Through-Thickness Residual Stresses in Girth Welded Pipes

1986 ◽  
Vol 108 (2) ◽  
pp. 99-106 ◽  
Author(s):  
E. F. Rybicki ◽  
J. R. Shadley
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Experimental Method ◽  
Three Dimensional ◽  
Element Model ◽  
Stress Distributions ◽  
Reference Stress ◽  
Improvement Process ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

The accuracy of a destructive, experimental method for the evaluation of through-thickness residual stress distributions is investigated. The application of the method is to a welded pipe that has been subjected to a residual stress improvement process. The residual stress improvement process introduces gradients in the stress distribution. The question of interest is how well the back-computation method used to interpret the experimental data represents the residual stress distribution for this type of stress profile. To address this question, a finite element model was used to provide a reference stress solution for comparison with the back-computation results of the experimental method. Three-dimensional finite element stress analyses were also conducted to simulate the cutting steps of the destructive laboratory procedure. The residual stress distributions obtained by the back-computation procedure were then compared with the reference stress solutions provided by the finite element model. The comparisons show agreement and indicate that good results can be expected from the experimental method when it is applied to a pipe that has been subjected to a residual stress improvement process, provided that the axial gradient of stress is not too large.

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.

Measurement of residual stresses in T-plate weldments

2003 ◽  
Vol 38 (4) ◽  
pp. 349-365 ◽  
Author(s):  
R. C Wimpory ◽  
P. S May ◽  
N. P O'Dowd ◽  
G. A Webster ◽  
D J Smith ◽  
...  
Keyword(s):  
Residual Stress ◽  
Neutron Diffraction ◽  
Plastic Zone ◽  
Residual Stresses ◽  
Plate Thickness ◽  
Welding Process ◽  
Plastic Zone Size ◽  
Hole Drilling ◽  
Stress Distributions ◽  
Premature Failure

Tensile welding residual stresses can, in combination with operating stresses, lead to premature failure of components by fatigue and/or fracture. It is therefore important that welding residual stresses are accounted for in design and assessment of engineering components and structures. In this work residual stress distributions, obtained from measurements on a number of ferritic steel T-plate weldments using the neutron diffraction technique and the deep-hole drilling method, are presented. It has been found that the residual stress distributions for three different plate sizes are of similar shape when distances are normalized by plate thickness. It has also been found that the conservatisms in residual stress profiles recommended in current fracture mechanics-based safety assessment procedures can be significant—of yield strength magnitude in certain cases. Based on the data presented here a new, less-conservative transverse residual stress upper bound distribution is proposed for the T-plate weldment geometry. The extent of the plastic zone developed during the welding process has also been estimated by use of Vickers hardness and neutron diffraction measurements. It has been found that the measured plastic zone sizes are considerably smaller than those predicted by existing methods. The implications of the use of the plastic zone size as an indicator of the residual stress distributions are discussed.

Three-Dimensional Numerical Simulation of Temperature Field and Force Field of T-Type Turbe during Welding

2013 ◽  
Vol 690-693 ◽  
pp. 2659-2663
Author(s):  
Jian Ping Zhou ◽  
Xiang Feng Zhang ◽  
Hong Sheng Liu ◽  
Jun Yi Gao ◽  
Yan Xu
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Temperature Field ◽  
Three Dimensional ◽  
Welding Process ◽  
Three Dimension ◽  
Analysis Software ◽  
Element Analysis ◽  
Cool Process ◽  
Type Tube

Residual stress affect the lifetime of weldments directly. Temperature Generated from the welding process is the major reason that influences the microstructure and mechanical properties of the metal weldments. Therefore it is necessary to simulate the temperature field for optimizing the structure of weldments. In this work the three-dimension finite element analysis software SYSWELS was used to simulate T-type tube, and carried on a detailed analysis of temperature field and residual stress in cool process of weld.

Numerical Investigation on Interruption in the Welding Process Used in Shipbuilding

2015 ◽  
Vol 31 (04) ◽  
pp. 220-229
Author(s):  
Debabrata Podder ◽  
Sara Kenno ◽  
Sreekanta Das ◽  
Nisith Ranjan Mandal
Keyword(s):  
Residual Stress ◽  
Heat Source ◽  
Complex Geometry ◽  
Time Lag ◽  
Welding Process ◽  
Diffraction Method ◽  
Nonlinear Material ◽  
Fe Model ◽  
Temperature Dependent ◽  
Longitudinal Residual Stress

Interruptions in the welding process in shipbuilding are unavoidable because of complex geometry and human fatigue. This article presents an uncoupled three dimensional finite element (FE) modeling technique for bead-on-plate welding and an interruption in the welding process for low carbon and high notch toughness steel plate typically used in shipbuilding. The goal of the FE model was to successfully predict the effect of various time delays in the welding interruption on the residual stress distributions. The FE results are compared with the experimental results for the validation of the model. The experimental work was completed using the neutron diffraction method. The element birth-and-death algorithm was used in ANSYSW to simulate the filler metal deposition. A double ellipsoid heat source was used to simulate the heat source of the weld pool. The FE model considers the temperature dependent nonlinear material properties and uses the temperature-dependent combined coefficient of heat loss. The study found that weld interruptions in the welding process change the residual stress patterns and cause an increase in the maximum longitudinal tensile residual stresses. However, the maximum longitudinal compressive stress reduces as a result of interruptions in the weld process. This study found that a weld interruption duration of approximately 2 minutes is optimum for both fatigue and buckling strength. This study also analyzed the effect of preheat on longitudinal residual stress distribution and concluded that a suitable short time lag without any preheat is equivalent to preheat after a long welding interval.

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