New Method for Fast Predictions on Residual Stress and Distortion of AM Parts

A new multi-scale approach based on the method of finite elements is developed in order to enable much faster predictions of residual stress and distortion for AM parts. The approach includes the calibration of the heat source, the analysis of scanning strategies, the generation of the so-called “mechanical layer equivalent” (MLE) and its integration into a fast structural analysis. The use of MLE determined on the micro-scale and mapped into the largescale structural analysis reduces computational time in comparison with the conventional thermo-mechanical simulations from months to hours while saving the same accuracy of numerical predictions. The new method is realized in newly developed powerful AM software. Simulation results are in a very good agreement with experimental measurements of distortion and residual stress. The potential of the new method to compensate the expected distortion using pre-deformation of parts is demonstrated by numerical experiments of a near-net-shape AM fabrication.