A multi-grain thermo-mechanical framework for part-scale modeling of laser powder bed fusion
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A multi-grain method is proposed for part-scale thermo-mechanical simulation of the laser powder bed fusion (L-PBF) process, with the aim of accounting for anisotropic mechanical behavior induced by the textured grain structure. First, the part-scale grain structure is generated using a hybrid cellular automaton (CA) approach, which enables grain evolution to be computed on a CA grid at part scale while incorporating detailed scanning trajectories. The resulting grain information is then transferred to a mechanical finite-element mesh through a grain distribution procedure, allowing the influence of grain structure on the mechanical response to be captured. A mechanical solver accounting for multi-grain effects is developed using a simple local solution based on crystal plasticity, in which each mechanical element is composed of the grains that contribute most significantly. The effectiveness and computational efficiency of the approach are evaluated using textured representative volume elements and through its application to L-PBF process simulations. The results are then compared with those obtained using a previously developed single-grain method.
