Temperature field in a hollow finite-length cylinder with an arbitrarily moving heat source

1972 ◽  
Vol 22 (3) ◽  
pp. 381-385 ◽  
Author(s):  
L. A. Brichkin ◽  
Yu. V. Darinskii ◽  
L. M. Pustyl'nikov
Keyword(s):  
Temperature Field ◽  
Heat Source ◽  
Finite Length ◽  
Moving Heat Source

scholarly journals Heat Source Modeling in Selective Laser Melting

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2052 ◽  
Author(s):  
Elham Mirkoohi ◽  
Daniel E. Seivers ◽  
Hamid Garmestani ◽  
Steven Y. Liang
Keyword(s):  
Temperature Field ◽  
Steady State ◽  
Heat Source ◽  
Material Properties ◽  
Physical Phenomenon ◽  
Three Dimensional ◽  
Moving Heat Source ◽  
Point Heat Source ◽  
Laser Melting ◽  
Source Models

Selective laser melting (SLM) is an emerging additive manufacturing (AM) technology for metals. Intricate three-dimensional parts can be generated from the powder bed by selectively melting the desired location of the powders. The process is repeated for each layer until the part is built. The necessary heat is provided by a laser. Temperature magnitude and history during SLM directly determine the molten pool dimensions, thermal stress, residual stress, balling effect, and dimensional accuracy. Laser-matter interaction is a crucial physical phenomenon in the SLM process. In this paper, five different heat source models are introduced to predict the three-dimensional temperature field analytically. These models are known as steady state moving point heat source, transient moving point heat source, semi-elliptical moving heat source, double elliptical moving heat source, and uniform moving heat source. The analytical temperature model for all of the heat source models is solved using three-dimensional differential equations of heat conduction with different approaches. The steady state and transient moving heat source are solved using a separation of variables approach. However, the rest of the models are solved by employing Green’s functions. Due to the high temperature in the presence of the laser, the temperature gradient is usually high which has a substantial impact on thermal material properties. Consequently, the temperature field is predicted by considering the temperature sensitivity thermal material properties. Moreover, due to the repeated heating and cooling, the part usually undergoes several melting and solidification cycles, and this physical phenomenon is considered by modifying the heat capacity using latent heat of melting. Furthermore, the multi-layer aspect of the metal AM process is considered by incorporating the temperature history from the previous layer since the interaction of the layers have an impact on heat transfer mechanisms. The proposed temperature field models based on different heat source approaches are validated using experimental measurement of melt pool geometry from independent experimentations. A detailed explanation of the comparison of models is also provided. Moreover, the effect of process parameters on the balling effect is also discussed.

Temperature Field Due to a Moving Heat Source: A Moving Mesh Finite Element Analysis

1985 ◽  
Vol 52 (2) ◽  
pp. 274-280 ◽  
Author(s):  
Z.-B. Kuang ◽  
S. N. Atluri
Keyword(s):  
Finite Element ◽  
Temperature Field ◽  
Heat Source ◽  
Process Zone ◽  
Surrounding Medium ◽  
Moving Mesh ◽  
Transient Temperature ◽  
Moving Heat Source ◽  
Element Analysis ◽  
External Agent

The transient temperature field (as seen by a moving observer) due to a moving heat source, such as the process zone near a dynamically propagating crack tip or an external agent as in the case of welding, is analyzed by a moving-mesh finite element procedure. The effects of the temperature-dependent material properties, and of the loss of heat to the surrounding medium through convection and radiation, are studied. Situations under which conditions in the process zone may be labeled as “isothermal” or “adiabatic” are explored. Estimates of temperature rise near the tip of a crack propagating at realistic speeds in structural steels are made.

scholarly journals Development of Finite Element Solver for Welding Analysis

2018 ◽  
Vol 2 (2) ◽  
Author(s):  
Abid Ali Khan ◽  
Farzeen Shahid ◽  
Ihtzaz Qamar
Keyword(s):  
Finite Element ◽  
Temperature Field ◽  
Heat Conduction ◽  
Heat Source ◽  
Welding Process ◽  
Transient Heat Conduction ◽  
Moving Heat Source ◽  
Structural Members ◽  
Final Solution ◽  
Governing Equations

Welding is a process of joining the similar or different metals. Improper welding process leads to inaccuracies and misalignments of structural members, causing high cost and delays in work. Therefore, it is essential to predict the temperature field during welding process. Different techniques can be used to predict the temperature field, which may lead to structure distortion. The present study aims to develop a finite element solver for transient heat conduction analysis. The final solution is calculated from the assumed solution and compared with the numerical computations. The solver is then modified for use of moving heat source. The modification comprise, change in governing equations with the inclusion of phase change. The moving heat source continuously increases the temperature during motion. When the heat source completes a pass, model is allowed to cool down in order to study the temperature distribution during cooling.

scholarly journals Heat Source Modeling in Selective Laser Melting

2019 ◽  
Author(s):  
Elham Mirkoohi ◽  
Daniel E. Seivers ◽  
Hamid Garmestani ◽  
Steven Y. Liang
Keyword(s):  
Temperature Field ◽  
Steady State ◽  
Heat Source ◽  
Material Properties ◽  
Physical Phenomenon ◽  
Three Dimensional ◽  
Moving Heat Source ◽  
Point Heat Source ◽  
Laser Melting ◽  
Source Models

Selective laser melting is an emerging Additive Manufacturing (AM) technology for metals. Intricate three-dimensional parts can be generated from the powder bed by selectively melting the desired location of the powders. The process is repeated for each layer until the part is built. The necessary heat is provided by a laser. Temperature magnitude and history during SLM directly determine the molten pool dimensions, thermal stress, residual stress, balling effect, and dimensional accuracy. Laser-matter interaction is a crucial physical phenomenon in the SLM process. In this paper, five different heat source models are introduced to predict the three-dimensional temperature field analytically. These models are known as steady state moving point heat source, transient moving point heat source, semi-elliptical moving heat source, double elliptical moving heat source, and uniform moving heat source. The analytical temperature model for all of the heat source models are solved using three-dimensional differential equation of heat conduction with different approaches. The Steady state and transient moving heat source are solved using separation of variables approach. However, the rest of models are solved by employing the Green’s functions. Due to the high magnitude of the temperature in the presence of the laser, the temperature gradient is usually high which has a substantial impact on thermal material properties. Consequently, the temperature field is predicted by considering the temperature sensitivity thermal material properties. Moreover, due to the repeated heating and cooling, the part usually undergoes several melting and solidification cycles, this physical phenomenon is considered by modifying the heat capacity using latent heat of melting. Furthermore, the multi-layer aspect of metal AM process is considered by incorporating the temperature history from the previous layer since the interaction of the layers have an impact on heat transfer mechanisms. The proposed temperature field models based on different heat source approaches are validated using experimental measurement of melt pool geometry from independent experimentations. The detailed explanation of the comparison of models is also provided. Moreover, the effect of process parameters on the balling effect is also discussed.

Effects of Change of Phase on Temperature Distribution Due to a Moving Heat Source

1975 ◽  
Vol 97 (1) ◽  
pp. 39-44
Author(s):  
C. S. Kang ◽  
Y. P. Chang
Keyword(s):  
Boundary Condition ◽  
Temperature Field ◽  
Temperature Distribution ◽  
Heat Source ◽  
Heat Input ◽  
Line Source ◽  
Initial Temperature ◽  
The Other ◽  
Heat Sources ◽  
Moving Heat Source

This paper presents a numerical method for the solution of problems of moving heat sources with change of phase and with any boundary condition. Calculated results of two specific cases are shown: one for a plane moving source in a rod and the other for a line source in a plate. It is found that for low heat input and/or low initial temperature, the change of phase does not affect significantly the temperature distribution in the medium, were it of solid only. However, the higher the heat input and/or the initial temperature, the larger is the effect of phase-change to the temperature field.

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