Finite element analysis of thermo-mechanical behavior of a multi-layer laser additive manufacturing process

Finite element analysis was utilized in this investigation to study the effect of varying the direction of the laser scan on the thermo-mechanical behavior of a multi-layer additive manufacturing (AM) process. The effect of varying the direction of laser rastering on the temperature distribution, strain, stress and deformation was analyzed in this study. Two laser rastering strategies were considered, namely, (a) counter-clockwise (CCW) for each of the layers deposited and, (b) alternating (CCW followed by clockwise) for each successive layer using a well-validated model. The results showed that for the geometrical configuration under consideration in this study, thermal strains were not significantly impacted by the rastering direction of the laser (CCW is lower than alternating by 8–9%). However, altering the direction of rastering leads to a 45–75% reduction in the deformation values as compared to the CCW mode. This co-relates well with the 10% difference in the maximum thermal gradient of the alternating case compared to the CCW case. The von Mises stress was found to be higher in the CCW mode as compared to the alternating mode. The findings of this investigation illustrated that the location of maximum shear stress depended on the direction of the laser rastering and followed the same trend observed in the thermal strain and the normal von Mises stress. Hence, the CCW mode was found to exhibit higher shear stresses compared with the alternating mode. This study clearly shows that the rastering direction of the laser beam has a profound effect on the thermo-mechanical behavior of the parts manufactured using AM processes. © 2022, The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.