Applications of moving heat sources, such as welding, are common in many industrial areas. In order to master these processes, numerical simulation is generally used. More often than not, it is the finite element method (FEM) that is used. But the FEM has multiple drawbacks related to the use of a mesh, which is a crucial concept of the method. An alternative becoming more attractive to overcome the inconvenience of the FEM is the use of meshless methods. Rather new, the knowledge related to some aspects of these methods is still limited.
In this master’s thesis, a computer code relying on the meshless Element-Free Galerkin (EFG) method was developed to solve an unsteady and three-dimensional conduction problem involving a moving heat source. The in-house code was then validated with the FEM and a commercial software. Good agreement was obtained between the results.
Next, experimental work was conducted, consisting of bead-on-plate MIG welds on 6061-T6 aluminum samples. Using four thermocouples located at various distances from the weld bead, the thermal curves were recorded and compared with numerical results. It was shown that the EFG method is able to correctly predict the peak temperatures and the cooling rates, despite the use of constant physical properties.
Lastly, a parametric study was conducted to determine the best parameters to use, i.e. the size and shape of the support domain, the weight functions and the required quantity of quadrature points. It was concluded that the sphere- or brick-shaped domain with a quantity of quadrature points ten times higher than the quantity of field nodes is a suitable choice.
| Date | 19 Apr 2020 |
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| Original language | French |
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| Awarding Institution | - École de technologie supérieure
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| Supervisor | Tan Pham (Supervisor) |
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Champagne, O. (Author),
Pham (Supervisor),
19 Apr 2020Student thesis: Master's thesis › Master in Engineering: Mechanical Engineering