No abstract

Additive manufacturing processes fulfill the actual market demands with regard to a high individuality and complexity of products. Hence, these processes are used nowadays in different branches (e. g. aerospace, automotive, medical industry). Further-more, a high process stability and reproducibility is requested by the user for an eco-nomic application of this technology. Up to now, these targets are reached by numer-ous test rigs on the manufacturing system which causes high resource consumption. For increasing the efficiency of metal-based additive manufacturing (AM), the em-ployees of the iwb application center Augsburg in corporation with the CADFEM GmbH and four further partners develops a simulation-based process chain (founded by the Bavarian Research Foundation). Before the production process is started, an analysis of the structural part behavior as well as a process optimization should be per-formed using the finite element analysis (FEA). Due to the complexity of the thermal-ly activated process, it is necessary to select the appropriate FE-modeling strategy for enhancing the target figures calculation efficiency and accuracy. Hence, in this work a strategy will be presented, which can map different levels of detail for the preprocess-ing definitions. These local and global descriptions can be realized by using suitable contact definitions (contact elements) to link different element meshes. Additionally, the user can select different layers of the part geometry, which should be analyzed in detail within the simulation. Also layer-specific distortions and residual stresses can be calculated while saving calculation time. Furthermore, with this approach the process history and therefore the whole part geometry can be considered in the structural cal-culations. A validation of the transient temperature field and the mechanical part properties is presented by the comparison with measured values.

Currently, the main field of application of additive manufacturing processes is shifting from research laboratories to production facilities. Simulation models can foster this transition by providing support in process development and design. This paper introduces approaches to modelling the beam-material interaction in laser beam melting on a level of detail that allows the simulation of the whole build-up process of parts, not only of single laser tracks. Thus both the achievable result accuracy and the needed calculation time are discussed. For this purpose, fundamental correlations to link process characteristics with model parameters are explained. Subsequently, four modelling approaches are analysed. After an introduction of the well-known method of applying a uniform load on a whole layer compound (e. g. [1]), the developed methods are discussed which allow modelling the beam-material interaction on a more detailed level. Thereby, the focus lies on the ability to model load gradients perpendicular to the build direction. This article is completed with a discussion of simulated temperature curves for selected monitoring points using two different modelling approaches.