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.

scholarly journals Simulating Convective-Radiative Heat Sinks Effect by means of FEA-based Gaussian Heat Sources and Its Approximate Analytical Solutions for Semi-Infinite Body

2021 ◽  
Author(s):  
Ninh The Nguyen ◽  
John H Chujutalli
Keyword(s):  
Temperature Field ◽  
Heat Source ◽  
Analytical Solutions ◽  
Radiative Heat ◽  
Source Model ◽  
Heat Sinks ◽  
Transient Temperature ◽  
Measured Temperature ◽  
Heat Source Model ◽  
Transient Temperature Field

Abstract FEA-based Gaussian density heat source models were developed to study the effect of convective and radiative heat sinks on the transient temperature field predicted by the available approximate analytical solution of the purely conduction-based Goldak’s heat source. A new complex 3D Gaussian heat source model, incorporating all three modes of heat transfer, i.e., conduction, convection and radiation, has been developed as an extension of the Goldak heat source. Its approximate transient analytical solutions for this 3-D moving heat source were derived and numerically benchmarked with the available measured temperature & weld pool geometry data by Matlab programming with ~5 to 6 times faster than FEA-based simulation. The new complex 3D Gaussian heat source model and its approximate solution could significantly reduce the computing time in generating the transient temperature field and become an efficient alternative to extensive FEA-based simulations of heating sequences, where virtual optimisation of a melting heat source (i.e. used in welding, heating, cutting or other advanced manufacturing processes) is desirable for characterisation of material behaviour in microstructure evolution, melted pool, microhardness, residual stress and distortions.

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.

Heat source model for laser beam welding of steel-aluminum lap joints

2017 ◽  
Vol 93 (1-4) ◽  
pp. 709-716 ◽  
Author(s):  
Anton Evdokimov ◽  
Katrin Springer ◽  
Nikolay Doynov ◽  
Ralf Ossenbrink ◽  
Vesselin Michailov
Keyword(s):  
Heat Source ◽  
Laser Beam ◽  
Laser Beam Welding ◽  
Source Model ◽  
Lap Joints ◽  
Heat Source Model

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.

scholarly journals Thermal Analysis Simulation for Laser Butt Welding of Inconel625 Using FEA

2018 ◽  
Vol 7 (4.10) ◽  
pp. 85 ◽  
Author(s):  
Harinadh Vemanaboina ◽  
G. Edison ◽  
Suresh Akella ◽  
Ramesh Kumar Buddu
Keyword(s):  
Heat Source ◽  
Residual Stresses ◽  
Laser Beam ◽  
Laser Welding ◽  
Process Parameters ◽  
Heat Input ◽  
Laser Beam Welding ◽  
Source Model ◽  
Heat Source Model ◽  
Welding Processes

Laser welding process is employed in the manufacturing of critical components where the final assembly units necessitate strict tolerances like low distortions and residual stresses. Laser beam welding offers several advantages like low heat input, very narrow heat affected zone, low residual stresses, low distortions and good mechanical joint properties in the weld joints when compared to the conventional techniques like Tungsten Inert Gas Arc welding processes. However, the implementation of laser beam welding holds certain challenges like process parameters optimization, experimental set-up and handling and expensive costs. In order to minimize the complex experimental process, simulation techniques using Finite Element Methods (FEM) are employed in order to estimate the heat input and weld process optimization prior to the experiments. This greatly helps in the optimization and estimation of the incurred stresses and distortions with the adapted weld process with known input weld process parameters. The present work reports the Gaussian heat source model for the laser welding of Inconel 625 Alloy plates. The developed moving heat source model is presented and demonstrated with the thermal profiles in terms of the thermal histogram, temperature profiles in the joint cross sections through welded region, interface across the joints.  

Sign in / Sign up

Export Citation Format

Share Document