Coupled Field Analysis of a Gas Tungsten Arc Welded Butt Joint—Part I: Improved Modeling

2013 ◽  
Vol 5 (1) ◽  
Author(s):  
D. Sen ◽  
M. A. Pierson ◽  
K. S. Ball
Keyword(s):  
Weld Pool ◽  
Welding Process ◽  
Butt Joint ◽  
Accurate Estimation ◽  
Mathematical Framework ◽  
Welded Structures ◽  
Thermally Induced ◽  
Gas Tungsten Arc ◽  
Welded Structure ◽  
Gas Tungsten

Thermally induced residual stresses due to welding can significantly impair the performance and reliability of welded structures. From a structural integrity perspective of welded structures, it is necessary to have an accurate spatial and temporal thermal distribution in the welded structure before stress analysis is performed. Existing research has ignored the effect of fluid flow in the weld pool on the temperature field of the welded joint. Previous research has established that the weld pool depth/width (D/W) ratio and heat affected zone (HAZ) are significantly altered by the weld pool dynamics. Hence, for a more accurate estimation of the thermally induced stresses it is desired to incorporate the weld pool dynamics into the analysis. Moreover, the effects of microstructure evolution in the HAZ on the mechanical behavior of the structure need to be included in the analysis for better mechanical response prediction. In this study, a three-dimensional numerical model for the thermomechanical analysis of gas tungsten arc (GTA) welding of thin stainless steel butt-joint plates has been developed. The model incorporates the effects of thermal energy redistribution through weld pool dynamics into the structural behavior calculations. Through material modeling the effects of microstructure change/phase transformation are indirectly included in the model. The developed weld pool dynamics model includes the effects of current, arc length, and electrode angle on the heat flux and current density distributions. All the major weld pool driving forces are included, namely surface tension gradient induced convection, plasma induced drag force, electromagnetic force, and buoyancy. The weld D/W predictions are validated with experimental results. They agree well. The workpiece deformation and stress distributions are also highlighted. The mathematical framework developed here serves as a robust tool for better quantification of thermally induced stress evolution and distribution in a welded structure by coupling the different fields in a welding process.

Simulation of Weld Pool Dynamics and Subsequent Thermal Stress Analysis of Welded Joint Under Gas Tungsten Arc Welding

2011 ◽  
Author(s):  
Debamoy Sen ◽  
Kenneth S. Ball ◽  
Mark A. Pierson
Keyword(s):  
Thermal Stress ◽  
Stress Analysis ◽  
Weld Pool ◽  
Thermal Stresses ◽  
Welding Parameters ◽  
Thermal Profile ◽  
Thermal Stress Analysis ◽  
Gas Tungsten Arc ◽  
Welded Structure ◽  
Gas Tungsten

Thermal stresses in the weldment influence the load carrying capacity of the welded structure and have significant practical implications. Various welding parameters (like, welding speed, current, surfactant activity, etc.) influence the weld pool dynamics, which in turn affect the thermal history of the workpiece. Hence, the complete weld pool dynamics need to be considered for predicting an accurate thermal profile in the welded structure before a thermal stress analysis is conducted. In this study, the thermal profile created due to fluid flow, heat transfer and phase change during Gas Tungsten Arc (GTA) welding is incorporated in conducting a thermal stress analysis of the welded workpiece. The effect of preheat on the developed thermal stresses is also analyzed.

scholarly journals Effect of Current on Mechanical Properties and Microstructure of Aluminum 6061 with Gas Tungsten Arc Welding Process

Kapal ◽  
2020 ◽  
Vol 17 (3) ◽  
pp. 107-113
Author(s):  
Tarmizi Tarmizi ◽  
Kevin Daniel Sianturi ◽  
Irfan Irfan
Keyword(s):  
Mechanical Properties ◽  
Arc Welding ◽  
Gas Flow ◽  
Welding Process ◽  
Butt Joint ◽  
Gas Tungsten Arc Welding ◽  
Welding Parameters ◽  
Gas Tungsten Arc ◽  
Gtaw Process ◽  
Gas Tungsten

Aluminum 6061 is an aluminum alloy that is widely used in various industrial fields, which heat treatable. However, it can be joined using a welding process. Aluminum joining using the Gas Tungsten Arc Welding (GTAW) process has become the option to produce good quality joints. This research aims to get optimum welding parameters by knowing the mechanical properties and microstructure of the welding results. The GTAW process uses a 25-volt voltage, Argon protective gas flow rate of 15 liters per minute with filler rod ER 5356 with 2.4 mm diameter and electrodes tungsten 2.4 mm in diameter. This process uses a single V butt joint and groove angle of 60° with variations in the current of 100, 110 and 120 A. The results indicate that specimens with a variety of current of 110 A give better results in the absence of defects, have a tensile strength of 152 MPa, and get a hardness value of 87.55 HV, which is the highest compared to the other two specimens. Whereas specimens with the current variation of 100 and 120 A have defects in the weld area. The optimum parameters of the 6061 aluminum GTAW process with a thickness of 6 mm using a current of 110 A bring on better outcomes and mechanical properties than the use of currents of 100 and 120 A.

Nonlinear Dynamic Modelling of Weld Penetration in Gas Tungsten Arc Welding Process

2013 ◽  
Vol 658 ◽  
pp. 292-297 ◽  
Author(s):  
Yu Kang Liu ◽  
Shu Jun Chen ◽  
Wei Jie Zhang ◽  
Yu Ming Zhang
Keyword(s):  
Linear Model ◽  
Weld Pool ◽  
Nonlinear Dynamic ◽  
Arc Welding ◽  
Welding Process ◽  
Gas Tungsten Arc Welding ◽  
Weld Penetration ◽  
Inference System ◽  
Gas Tungsten Arc ◽  
Gas Tungsten

Skilled welders can estimate and control the weld penetration based on weld pool observation. This implies that an advanced control system could be developed to control the penetration by emulating the decision making process of the human welder. In this paper a nonlinear dynamic model is established to correlate the process inputs (welding current and traveling speed) and weld penetration in Gas Tungsten Arc Welding (GTAW). An innovative 3D vision sensing system capable of measuring the weld pool characteristic parameters in real-time is utilized. Dynamic experiments are conducted under various welding conditions. Dynamic linear model is first constructed and the results are analyzed. The linear model is then improved by incorporating a nonlinear operating point modeled by Adaptive Neuro Fuzzy Inference System (ANFIS). It is found that the penetration state can be better modeled by the proposed ANFIS model.

Determination of some Mechanical Characteristics by Vibration Testing of Welded Structures with Tubular Wire

2013 ◽  
Vol 814 ◽  
pp. 127-134 ◽  
Author(s):  
Liviu Bereteu ◽  
Raul Moisa ◽  
Mihaela Popescu ◽  
Gheorghe Drăgănescu ◽  
Radu Alexandru Rosu ◽  
...  
Keyword(s):  
Steel Wire ◽  
Welding Process ◽  
Tensile Tests ◽  
Operating Conditions ◽  
Steel Plates ◽  
Vibration Testing ◽  
Welded Structures ◽  
Appropriate Behavior ◽  
Welded Structure

Applicability of the welded structures in different operating conditions requires experimental research developed in conditions previously imposed for each punctual application. There are analyzed in this case, in terms of vibration testing, some welded joints made with usual tubular steel wire. This is the case of the type carbon steel plates S235 JR according to EN 10025, with a thickness of 3 mm welded with MIG/MAG welding process with R713 tubular wire with a diameter of 1.2 mm, using SelcoNeoMig 3500 equipment. By processing the received signal based on the vibrations response to determine the elastic modulus of the welded structure, which will then be compared both with the modulus value obtained by tensile tests, and with the theoretical value obtained. The results thus obtained will be the basis of design, in optimal conditions of the welded structures regarding the appropriate behavior to the demands imposed.

Implementation of an Outer Can Welding System for Savannah River Site Plutonium Processing Facility

2003 ◽  
Author(s):  
S. Howard ◽  
W. Daugherty ◽  
C. Sessions
Keyword(s):  
Weld Pool ◽  
Savannah River Site ◽  
Phase Iii ◽  
Acceptance Testing ◽  
Savannah River ◽  
Gas Tungsten Arc ◽  
Processing Facility ◽  
Gas Tungsten ◽  
River Site ◽  
Three Phases

This paper details three phases of testing to confirm use of a Gas Tungsten Arc (GTA) system for closure welding the 3013 outer container used for stabilization/storage of plutonium metals and oxides. The outer container/lid closure joint was originally designed for laser welding, but for this application, the gas tungsten arc (GTA) welding process has been adapted. The testing progressed in three phases: (1) system checkout to evaluate system components for operational readiness, (2) troubleshooting to evaluate high weld failure rates and develop corrective techniques, and (3) pre-installation acceptance testing. A total of 190 can/lid welds were made and evaluated. During Phase I, weld failures were common due to pressure buildup and venting through the weld pool. During Phase II, characterization of the electrode contact to the weld pool and weld pool blowouts helped in the development of a corrective technique. During Phase III, a reduction in internal pressure, by controlling the final helium backfill of the can before welding, provided satisfactory weld results. The work described was performed during 2002 pre-installation testing at the Savannah River Technology Center in Aiken, S.C. before installation of an Outer Can Welder (OCW) system at the Savannah River Site (SRS) plutonium processing facility. The first OCW system was originally developed at the SRS to support similar plutonium stabilization/storage efforts at the Hanford Site (operated by Fluor Hanford Corporation).

Sign in / Sign up

Export Citation Format

Share Document