Análise térmica tridimensional do processo de soldagem a LASER por meio de simulação computacional em linguagem CUDA-C

Abstract

This work presents a numerical model to LASER welding process thermal analysis. The mathematical model based in the nonlinear transient three-dimensional heat diffusion equation. Associated with this model, the heat transfer effects by natural convection and radiation, physical phenomena present in the analyzed welding process, were considered as boundary conditions. To represent the heat flux from the LASER welding torch, the three-dimensional conical distribution was used, in order to obtain a better representation of the weld bead shape. The mathematics model solution, in turn, was based on the finite volume method. Its application is justified because it results in approximate equations obtained through energy conservation balance in the elementary volume. This numerical model was organized into programming routines developed in CUDA-C language, which enabled the numerical simulations execution on NVIDIA® GTX 1660 Ti GeForce GPU. With its use, there was a considerable computational time reduction, due to the SOR solver execution routines parallelization. For the validation of the proposed numerical model, a low penetration LASER welding process thermal analysis was performed. From the obtained results, there was good agreement between the proposal model and the ex- periment. Furthermore, the simulations allowed the weld bead profile prediction, showing low deviations for its width and penetration obtained numerically and experimentally. Finally, with the numerical model, it was possible to verify the importance of conside- ring the thermal conductivity and the specific heat at constant pressure variation with temperature.