scholarly journals The Influence of Welding Heat Source Inclination on the Melted Zone Shape, Deformations and Stress State of Laser Welded T-Joints

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5303
Author(s):  
Zbigniew Saternus ◽  
Wiesława Piekarska ◽  
Marcin Kubiak ◽  
Tomasz Domański

The paper concerns the numerical analysis of the influence for three different of welding heat source inclinations on the weld pool shape and mechanical properties of the resulting joint. Numerical analysis is based on the experimental tests of single-side welding of two sheets made of X5CrNi18-10 stainless steel. The joint is made using a laser welding heat source. Experimental test was performed for one heating source inclination. As a part of the work metallographic tests are performed on which the quality of obtained joints are determined. Numerical calculations are executed in Abaqus FEA. The same geometrical model is assumed as in the experiment. Material model takes into account changing with temperature thermophysical properties of austenitic steel. Modeling of the motion of heating source is performed in additional subroutine. The welding source parameters are assumed in accordance with the welding process parameters. Numerical calculations were performed for three different inclinations of the source. One inclination is consistent with experimental studies. The performed numerical calculations allowed to determine the temperature field, shape of welding pool as well as deformations and stress state in welded joint. The obtained results are compared to results of the experiment.

2016 ◽  
Vol 62 (3) ◽  
pp. 207-224 ◽  
Author(s):  
M. Superczyńska ◽  
K. Józefiak ◽  
A. Zbiciak

Abstract The paper presents results of numerical calculations of a diaphragm wall model executed in Poznań clay formation. Two selected FEM codes were applied, Plaxis and Abaqus. Geological description of Poznań clay formation in Poland as well as geotechnical conditions on construction site in Warsaw city area were presented. The constitutive models of clay implemented both in Plaxis and Abaqus were discussed. The parameters of the Poznań clay constitutive models were assumed based on authors’ experimental tests. The results of numerical analysis were compared taking into account the measured values of horizontal displacements.


Author(s):  
Mohsen Ghazanfari ◽  
Parisa Hosseini Tehrani

Continuously welded rails are widely used in the Iran railway network, which are generally built using the flash-butt welding process. To accurately model the flash-butt welding process, thermal analysis, and prediction of the welding residual stresses, the influence of upsetting force on the total electrical resistance and a material model with consideration of the influence of temperature on the material properties are included in the numerical modeling. In this paper, numerical and experimental studies, including the finite element method, thermography, metallography, and hardness testing are performed to determine the characteristics of the welded UIC60 rail. By studying the fractured flash-butt welded UIC60 rails, it is shown that the location of the crack initiation and the rail failure in the web and heat affected zone of the welded rails was similar as compared to the maximum tensile residual stress calculated by numerical simulation. According to the numerical and experimental results, it is shown that four key parameters – such as the maximum temperature during the welding process, the total welding time, the upsetting time, and the upsetting force – control the size, microstructure, and the hardness profile of the heat affected zone which directly affects the characteristics and quality of welding.


Author(s):  
M Sitarz ◽  
A Sladkowski ◽  
K Bizoń ◽  
K Chruzik

Current design process can be simplified and accelerated, if computer simulation based on finite element method (FEM) is used. FEM numerical calculations of different wheels of railway wheelsets are investigated in the Department of Railway Engineering. The justification for undertaking this issue is that there is no methodology in the design of railway wheelsets both in Poland and abroad. In order to assess the calculation model, experimental tests of static loads (due to carriage weight) and thermal loads (due to braking) have been run. The results of these tests have been compared with the results of numerical analysis. The proposed calculation model has been compared with the results of test stand investigation. Comparison of the results has confirmed the correctness of the proposed discrete model and calculation algorithm. In the framework of the common scientific-didactic projects of Railway Engineering Department and Central Rail Research Institute in Moscow and producer of railway wheelsets-BONATRANS a.s. in Bohumin (Czech Republic), the method was worked out, and the experimental researches were conducted on specialists certified stands for railway wheelset researches (Sitarz, M., Bizoń, K., and Chruzik, K. Numerical calculations reckonings of railway wheel sets. W: Scientific Proceedings of Riga Technical University, 2002, str 84-89, Sladkowski, A., Bizoń, K., and Chruzik, K. Porównanie wyników analizy MES z wynikami pomiarów tensometrycznych deformacji kól kolejowych zestawów kolowych, Zeszyty Naukowe Katedry Mechaniki Stosowanej nr 18/2002, Gliwice, 2002, str 397-402, Zima, R., Bizoń, K., Chruzik, K. Badania teoretyczne i eksperymentalne kól kolejowych zestawów kolowych, W: XLII Sympozjon ‘Modelowanie w mechanice’, Wisla, 2003).


2020 ◽  
Author(s):  
A Karpagaraj ◽  
SURESH KUMAR S ◽  
S Thamizhmanii ◽  
Arun Nelliappan T ◽  
Siva Shanmugam N ◽  
...  

Abstract Numerical simulation is widely used in all the fields of engineering to predict the results. In welding, various finite element tools are used to predict the bead profile, temperature distribution, joint strength, formability and metallurgical changes etc. With respect to the welding process suitable heat source model has to be assigned for numerical simulation. The most suitable heat source for Gas Tungsten Arc Welding (GTAW) process is the Goldack double ellipsoidal model. This model has few parameters like the width of the weld (a), depth of penetration (b), front profile ellipse (Cf) and rear ellipse profile (Cr). In this research article, the influence of these parameters and their effect on the temperature distribution is focused. For this purpose, based on the full factorial design welding simulations are performed with COMSOL. Later, the grey relational technique was used to find the contribution of these parameters. It was concluded from the full factorial method that; temperature variation is depended on the GTAW welding heat source parameters. At 95% confidence level, the width of the weld showed a major role in controlling the temperature. Moreover, the optimum combination of process variables obtained end with minimum temperature rise at a width of 0.7 mm, depth of 5.7 mm and frontal factor of 4.


Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 469 ◽  
Author(s):  
Adam Pelesz ◽  
Tomasz Czapka

The charging process of water droplets in different electrification systems using empirical and numerical analysis is described. A simplified model based on capacitance distribution is proposed. The results of the experimental studies and numerical calculations enable comparison of the induction and conduction charging methods in terms of the droplet charging level, described by the Q/m parameter. Research findings indicate that the conduction method in a 3-electrode system is the most effective among all the considered methods. It has been also shown that the application of a 2-electrode system under certain conditions provides greater Q/m parameter values in comparison to the system with three electrodes using the induction method. The research results can be used to develop charging systems (e.g., nozzles) that produce streams with electrically charged liquid particles.


Entropy ◽  
2019 ◽  
Vol 21 (10) ◽  
pp. 954
Author(s):  
Joanna Wróbel ◽  
Adam Kulawik

The basic problem of the numerical model’s quenching process is establishing the characteristics of the boundary conditions. The existing descriptions of the boundary conditions, which represent the parameters of equipment used in heat treatment processes, do not accurately reflect the actual process conditions. In the present study, the method of choice for superficial heat source parameters for TIG (tungsten inert gas) heating is modeled using artificial neural networks (ANN) and the finite element method (FEM). A comparison of the calculations obtained from the numerical model of non-steady state heat transfer with the results of the experimental studies is presented. The possibility of using ANN to compute the parameters of the boundary conditions for the heating treatment is analyzed. A multilayer feed-forward backpropagation network is developed and trained using value of temperature in the selected nodes obtained from numerical simulation.


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