Thermo-elastoplastic Simulation of Selective Laser Melting Processes with Multi-Level hp-Adaptive Finite Cell Method

Selective laser melting (SLM) has emerged as a very promising technique for creating highly complex and customized metal structures on the basis of digital models. It is achieved by successively joining layers of material of different shapes, where metal powder is fused together with the help of a laser. The overall process can be described as a coupled thermo-elastoplastic problem on an evolving domain. However, there are numerous challenges in simulating the SLM process, in order to compute the dimensional accuracy and the residual stresses of the end product. One challenge is to create a transient geometric discretization (e.g. by finite elements) during the process. In order to tackle this, the Finite Cell Method (FCM) [1], a high-order immersedboundary approach, is employed in our approach. Another challenge is that the phase change of the material takes place in a highly localized moving region around the laser, leading to strong gradients in temperature and mechanical stresses. Therefore, the discretization scheme should be able to adapt to the moving laser. This contribution will present a multi-level hp-adaptive Finite Cell Method proposed by Zan-der et al. [2] being integrated in a multi-physics framework to simulate the thermo-mechanicalprocess. Three-dimensional examples demonstrate capabilities and limitations of this new dis-cretizational approach. REFERENCES[1] Düster, A., Parvizian, J., Yang, Z., and Rank, E. (2008). The finite cell method for three-dimensional problems of solid mechanics. Computer Methods in Applied Mechanics andEngineering, 197:3768-3782.[2] Zander, N., Bog, T., Kollmannsberger, S., Schillinger, D. and Rank, E (2015). Multi-Level hp-Adaptivity: High-Order Mesh Adaptivity without the Difficulties of Constrain-ing Hanging Nodes, Computational Mechanic, 55:499-517, DOI: 10.1007/s00466-014-1118-x