NUMERICAL SIMULATION OF LASER GLAZING AND LASER DEPOSITION PROCESSES USING COUPLED TEMPERATURE-DISPLACEMENT FEM MODELS

摘要

Predicting the changes in the temperature, displacement and stress fields during Laser Powder Deposition (LPD) is of particular importance. To create a FEM model of LPD, it is convenient to consider first Laser Glazing (LG) since it does not involve the addition of material. Once an adequate approach has been identified to model the thermal aspects associated with the effect of the laser, the complexity of adding material can be included. In this paper coupled temperature-displacement FEM models of LG and LPD developed using the commercial FEM code ABAQUS/Standard are presented.In the case of LG, a model based on the sequentially coupled thermo-mechanical theory was used to predict the temperature distribution, deformations and stresses in a rectangular plate on which the laser moved along a straight path. The results for the temperature distribution were validated using Rosenthal's solution and experiments performed using the same material and processing parameters. For LPD, the model was developed using fully coupled thermo-mechanical theory and it was limited to thin-wall builds deposited on a plate with dimensions comparable to the wall thickness. To add material, new elements were sequentially introduced in the mesh. Qualitatively, the results obtained with the model were promising.