Verzugsminimierung bei selektiven Laserschmelzverfahren durch Multi-Skalen-Simulation

Abstract

In this work an effcient method for the prediction of residual stresses and distortions of parts generated by the additive manufacturing process Laser Beam Melting (LBM) is presented. The method allows to calculate the LBM build-up process at least 100 times faster than state-of-the-art approaches for realistic macroscopic components based on a structural Finite Element Analysis. The developed approach is based on the fact, that remaining strains cause the residual stresses within the part. These inherent strains can be derived by complex thermo-mechanical simulations on microscale. Based on the known stress and strain distribution during the process, scanning trajectories were optimized with respect to the reduction of end deformations, plastic strains and stresses during the build-up process. Based on the calculated displacements after the release from the baseplate, distortions can further be minimized by at least factor ten for one iteration if inverted displacements are back-mapped to the computer aided design. The combination of these two simulation driven methods leads to a nearly zero distortion fabrication while process stability rises.