The distributed heat source modeling method for the finite element simulation of IGBTs

Author(s):  
Jie Chen ◽  
Erping Deng ◽  
Zixuan Zhao ◽  
Yongzhang Huang
2018 ◽  
Vol 242 ◽  
pp. 01022
Author(s):  
Liu Heping ◽  
Sun Fenger ◽  
Yibo Fenger ◽  
Cheng Shaolei ◽  
Liu Bin

In this paper, the finite element simulation of GH4169 high temperature alloy by selective laser melting was carried out, and the microstructure was analyzed by experiments. The results show that the shape of the temperature field cloud formed by the laser heat source is different from the shape of the theoretical model, but is in the shape of the ellipse. The temperature gradient at the front end of the molten pool is larger than that of the back end of the molten pool, and the isotherm of the front end of the molten pool is more intensive. The temperature of the substrate is less affected by the temperature gradient. The temperature gradient of the front end of the melting pool is larger than the back end of the molten pool, and the temperature field of selective laser melting is like a meteor with trailing tail. In the laser heat source, the temperature isotherm is the most dense and the temperature gradient is maximum. The relative effect of mechanical properties of δ phase is very complex. When the phase is precipitated by widmanstatten structure, it is easy to produce stress concentration as a source of cracks


2011 ◽  
Vol 134 (1) ◽  
Author(s):  
S. Feli ◽  
M. E. Aalami Aaleagha ◽  
M. Foroutan ◽  
E. Borzabadi Farahani

In this paper, a finite element simulation, based on abaqus software is presented for analyzing the temperature history and the residual stress states in multipass welds in stainless steel pipe. The uncoupled thermal–mechanical a three-dimensional (3D) model and a two-dimensional (2D) model are developed. The volumetric heat source with double ellipsoidal distribution for front and rear heat source, proposed by Goldak and Akhlaghi, has also been used. Furthermore, a moving heat source has been modeled by abaqus subroutine DFLUX. A user subroutine FILM has also been used to simulate the combined thermal boundary conditions. The results of both a 3D model and a 2D axisymmetric model which are compared with the available experimental measurements show good agreements. Predictions show that the axial and hoop residual stresses in a 3D model and a 2D axisymmetric model have the same distributions in all locations except the starting point of welding. The effects of welding sequences on the thermal and structural analysis are also investigated. Four types of welding sequences for circular welds of pipe have been used and thermal history and axial and hoop residual stresses are compared. Predictions show that for other locations (except the starting point of welding) there are no important differences of axial and hoop residual stresses for welding sequences and they have the same distribution along axial direction.


2019 ◽  
Vol 9 (7) ◽  
pp. 1445 ◽  
Author(s):  
Feng Li ◽  
Jinqiang Ning ◽  
Steven Liang

The planar induction heating possesses more difficulties in industry application compared with traditional spiral induction coils in mostly heat treatment processes. Numerical approaches are adopted in the power distribution and temperature prediction during the induction heating process, which has a relatively low computational efficiency. In this work, an analytical calculation model of the planar induction heating with magnetic flux concentrator is investigated based on the uniform moving heating source. In this model, the power density in the surface of the workpiece induced by coils is calculated and applied into the analytical model of the temperature calculation using a uniform moving heat source. Planar induction heating tests are conducted under various induction coil parameters and the corresponding temperature evolution is obtained by the infrared imaging device NEC R300W2-NNU and the thermocouples. The final surface temperature prediction is compared to the finite element simulation results and experimental data. The analytical results show a good match with the finite element simulation and the experimental results, and the errors are in reasonable range and acceptable. The analytical model can compute the temperature distribution directly and the computational time is much less than the finite element method. Therefore, the temperature prediction method in this work has the advantage of less experimental and computational complexity, which can extend the analytical modeling methodology in induction heating to a broader application.


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