ESTABLISHMENT OF SEGMENTED MOVING DOUBLE ELLIPSOID HEAT SOURCE MODEL IN ELECTRON BEAM WELDING NUMERICAL SIMULATION

2004 ◽  
Vol 40 (02) ◽  
pp. 165 ◽  
Author(s):  
Yu Wang
Keyword(s):  
Numerical Simulation ◽  
Electron Beam ◽  
Heat Source ◽  
Electron Beam Welding ◽  
Source Model ◽  
Heat Source Model

Heat source model for electron beam welding of nickel-based superalloys

2021 ◽  
Vol 63 (1) ◽  
pp. 17-28
Author(s):  
Torsten Jokisch ◽  
Nikolay Doynov ◽  
Ralf Ossenbrink ◽  
Vesselin Georgiev Michailov
Keyword(s):  
Electron Beam ◽  
Heat Source ◽  
Electron Beam Welding ◽  
Experimental Studies ◽  
Theoretical Models ◽  
Source Model ◽  
Beam Deflection ◽  
Prediction Algorithm ◽  
Model Parameters ◽  
Heat Source Model

Abstract An adapted heat source model is developed for transient thermal numerical analysis of electron beam welded nickel-based alloy with increased susceptibility to hot cracking. The model enables the consideration of heat redistribution due to beam deflection phenomena. The modeling concept is validated by the appropriate theoretical models and in addition, experimental studies especially performed for this purpose. Special attention is given to the calibration of heat source model parameters. The calibration procedure is based on a statistical approach involving a combination of novel analytical solutions and quasi-steady state finite element models. The model parameter field is statistically analyzed, and a prediction algorithm is developed using optimization algorithms from the six sigma theory. The reliability and practicability of the model is demonstrated by validation weldments. The work is dedicated to precisely calculating the temperature field in the high temperature region around the weld pool and thus to provide a more detailed explanation of the formation of hot cracks when welding turbine materials commonly used in industry and aircraft constructions.

Influence of Forming Residual Stresses on the Welding Distortions of Two Thick Plates

2009 ◽  
Vol 83-86 ◽  
pp. 125-132 ◽  
Author(s):  
Sebastien Gallée ◽  
Antoine Martin ◽  
Vincent Robin ◽  
Daniel Nelias
Keyword(s):  
Numerical Simulation ◽  
Electron Beam ◽  
Heat Source ◽  
Residual Stresses ◽  
Electron Beam Welding ◽  
Initial Conditions ◽  
Rolling Process ◽  
Vacuum Vessel ◽  
Thick Plates ◽  
Simulation Results

The manufacturing of the ITER (International Thermonuclear Experimental Reactor) vacuum vessel involves the welding of thick deformed plates. The aim of this study is to investigate the influence of forming residual stresses on the welding distortions of two thick plates. The plates are deformed using a three point rolling process. A first numerical simulation is performed to investigate the residual stresses induced by this process. The forming residual stresses are taken into account as initial conditions to perform the electron beam welding simulation of a deformed plate. This simulation first requires calibrating the heat source. Two welding simulations are then performed: the first one with residual stresses and the second one without. The comparison of the simulation results points out a low effect of the residual stresses on the electron beam welding distortions. As a result, in the next electron beam welding simulations of the vacuum vessel, no forming residual stresses will be taken into account.

Multiscale modeling of electron beam and substrate interaction: a new heat source model

2015 ◽  
Vol 56 (2) ◽  
pp. 265-276 ◽  
Author(s):  
Wentao Yan ◽  
Jacob Smith ◽  
Wenjun Ge ◽  
Feng Lin ◽  
Wing Kam Liu
Keyword(s):  
Electron Beam ◽  
Heat Source ◽  
Multiscale Modeling ◽  
Source Model ◽  
Heat Source Model ◽  
Substrate Interaction

Modeling of the Temperature Field during Electron Beam Welding of Aluminum Alloy by a Pre-Defined Keyhole

2007 ◽  
Vol 353-358 ◽  
pp. 2011-2014
Author(s):  
Yan Hong Tian ◽  
Chun Qing Wang ◽  
Dan Yang Zhu
Keyword(s):  
Temperature Field ◽  
Electron Beam ◽  
Heat Source ◽  
Electron Beam Welding ◽  
Three Dimensional ◽  
Source Model ◽  
Transient Temperature ◽  
Al Alloy ◽  
Welding Pool ◽  
Welding Line

The transient temperature field of Al alloy during electron beam welding (EBW) process was simulated using a three-dimensional finite element method. Different from the most previous models which were based on the assumption that the welding pool was solid and neglected the existence of keyhole by meshing the solid as a whole, a dynamic three-dimensional keyhole was applied in this model. The profile of the keyhole was ellipse and its size was determined before simulation based on the results of experiments. Following the heat source, the pre-defined keyhole moved along the welding line. A three-dimensional complex heat source model, including a modified Gaussian distribution source and a uniform source, was used in this study. The result shows that the shape of the keyhole had a direct effect on the temperature distribution and contribution to the special shape of the welding pool in EBW.

Numerical and Experimental Studies of Residual Stresses in Multipass Welding of High Strength Shipbuilding Steel

2015 ◽  
Vol 59 (03) ◽  
pp. 133-144
Author(s):  
Guangming Fu ◽  
Tetyana Gurova ◽  
Marcelo I. Lourenco ◽  
Segen F. Estefen
Keyword(s):  
Neural Network ◽  
Numerical Simulation ◽  
Heat Source ◽  
Residual Stresses ◽  
Experimental Studies ◽  
Source Model ◽  
Fe Model ◽  
Offshore Platforms ◽  
Heat Source Model ◽  
Shipbuilding Industry

The article contributes, through numerical simulation based on models calibrated by experimental results, to better estimate residual stresses and distortions in welded structures representatives of ships and offshore platforms considering welding procedures relevant to shipyard current practices. A multi-pass welding is carried out to investigate the residual stresses in laboratory tests. The temperature at several positions on a plate sample is recorded with thermocouples and residual stresses are measured using an x-ray diffraction technique. Finite element (FE) models are developed in this study and experimentally validated. The three dimensional (3D) moving Goldak's double-ellipsoidal heat source model is employed in the simulations. A Levenberg-Marquardt neural network algorithm is employed to determine the geometric parameters of the heat source model. The technique based on neural network is applied to dimension the heat source later employed in the thermal analysis using 2D FE model to reduce the computer time of the numerical simulation and to make it feasible for shipbuilding industry applications. The numerical results of temperature and residual stress distribution are correlated with the experimental measurements. Finally, the effects of preheat and interpass temperatures on the residual stresses are investigated using numerical simulation. The effects of the transient releasing temperature on the residual stresses are also discussed.

scholarly journals Numerical Analysis of the Influence of Electrode Inclination on Temperature Distribution during GMAW Overlaying

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Jerzy Winczek ◽  
Marek Gucwa ◽  
Miloš Mičian ◽  
Krzysztof Makles
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Theoretical Model ◽  
Temperature Distribution ◽  
Numerical Analysis ◽  
Heat Source ◽  
Analytical Description ◽  
Source Model ◽  
Heat Source Model ◽  
Inclination Angles

In the work, an analysis of the influence of electrode inclination on the distribution of temperature in the weld overlaying has been conducted. In the analytical description of the temperature field, a volumetric heat source model with an inclined axis with respect to the direction of surfacing was adopted. In the numerical simulation, the own theoretical model of heat source, algorithm, and program performed in the Borland Delphi environment were used. In the calculation examples, different electrode inclination angles were adopted in relation to the welded plate, in the direction of surfacing, opposite to the direction of welding, and perpendicular to the weld bead.

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