Domain decomposition applied to the thermal model of selective beam melting processes

Abstract

ErlangenThe utilization of additive manufacturing enables the realization of rather complex part geometries. In the context of powder bed-based selective beam melting processes, parts are built in a layer-by-layer fashion by locally fusing powdered material using either a laser or electron beam. The simulation of powder bed-based additive manufacturing processes for both, polymers as well as metals, is usually a computationally expensive task. This is especially due to the different involved time and length scales, highly non-linear material behaviour and dynamic growth of the simulation domain. Hence, several numerical methods are ought to be combined in order to reduce the associated computational cost. Therefore we employ adaptivity in the spatial and temporal domain. This allows to have locally refined regions that are currently exposed to the beam, while coarsening the discretization in areas that are currently not exposed to the beam. In addition the path of the heat input is integrated in time, which renders a line heat input model. Furthermore, domain decomposition (Multi-Time-Stepping) is applied to account for the different requirements regarding the temporal discretization of different parts of the considered domain. This renders a time integration scheme with distinct time step sizes for different partitions of the domain.