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.

Nonlinear Optimization Methods for the Determination of Heat Source Model Parameters

2016 ◽  
Vol 879 ◽  
pp. 2008-2013
Author(s):  
Udo Hartel ◽  
Alexander Ilin ◽  
Steffen Sonntag ◽  
Vesselin Michailov
Keyword(s):  
Experimental Data ◽  
Heat Source ◽  
Parameter Identification ◽  
Nonlinear Optimization ◽  
Laser Beam Welding ◽  
Source Model ◽  
Transient Temperature ◽  
Surface Model ◽  
Model Parameters ◽  
Heat Source Model

In this paper the technique of parameter identification is investigated to reconstruct the 3D transient temperature field for the simulation of laser beam welding. The reconstruction bases on volume heat source models and makes use of experimental data. The parameter identification leads to an inverse heat conduction problem which cannot be solved exactly but in terms of an optimal alignment of the simulation and experimental data. To solve the inverse problem, methods of nonlinear optimization are applied to minimize a problem dependent objective function.In particular the objective function is generated based on the Response Surface Model (RSM) technique. Sampling points on the RSM are determined by means of Finite-Element-Analysis (FEA). The scope of this research paper is the evaluation and comparison of gradient based and stochastic optimization algorithms. The proposed parameter identification makes it possible to determine the heat source model parameters in an automated way. The methodology is applied on welds of dissimilar material joints.

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.

Estimation of heat source model parameters for twin-wire submerged arc welding

2009 ◽  
Vol 45 (11-12) ◽  
pp. 1096-1103 ◽  
Author(s):  
Abhay Sharma ◽  
Ajay Kumar Chaudhary ◽  
Navneet Arora ◽  
Bhanu K. Mishra
Keyword(s):  
Heat Source ◽  
Arc Welding ◽  
Source Model ◽  
Submerged Arc Welding ◽  
Model Parameters ◽  
Heat Source Model ◽  
Submerged Arc

scholarly journals Numerical Simulation and Experimental Research on Temperature Distribution of Fillet Welds

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1222 ◽  
Author(s):  
Shanchao Zuo ◽  
Ziran Wang ◽  
Decheng Wang ◽  
Bing Du ◽  
Peng Cheng ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Temperature Distribution ◽  
Heat Source ◽  
Matrix Equation ◽  
Source Model ◽  
Fillet Welds ◽  
Model Parameters ◽  
Heat Source Model ◽  
Fillet Weld ◽  
The Matrix

In this paper, a matrix equation for the welding heat source model was proposed to calculate the fillet welds temperature distribution based on the penetration depth and molten width. A double ellipsoid heat source model of fillet weld was established firstly by physical experiment and simulation calculation, and then the orthogonal experiment was constructed based on the previous calculation methods and experimentally measured data. Finally, the matrix equation of the heat source model parameters was obtained by regression analysis based on the joint penetration and width. The experimental and numerical simulation of the temperature distribution had been performed for the fillet weld and the results show that (1) the heat flux increases in one direction, while, oppositely, it decreased in another direction; (2) simulation results were highly in accordance with experiments results. The results indicated that the double ellipsoidal heat source model calculated by the matrix equation is quite appropriate for predicting the transient temperature distribution on the fillet welds for the gas metal arc welding process.

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