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H. Koch, R. Gómez Vázquez, A. Otto:
"Analysis of Distortion Effects on Weld Pool Dynamics in Laser Beam Welding";
Talk: IWOTE 2014, Bremen (Deutschland); 04-09-2014 - 04-10-2014; in: "Proceedings of the IWOTE 2014: International Workshop on Thermal Forming and Welding Distortion", Strahltechnik / BIAS Verlag, Volume 54 / 2014 / Bremmen (2014), ISBN: 978-3-933762-48-1; 165 - 172.

Laser welding belongs to the most frequently used industrial laser applications. Simulations can be used to find suitable process parameters for the industrial user of this joining technology. Effects of heat induced distortion play a crucial role in this laser material process. The understanding, how the distortion interacts with the melt pool dynamics, is of great importance to achieve sound weld seams. In this paper we describe a numerical model which is capable to simulate the highly complex coupled physics of laser welding. The numerical solution algorithms are modelled within the OpenFOAM framework. A dynamic mesh refinement method is used to ensure the necessary accuracy at low cost for memory and computation time. The simulation model includes the coupled physics of phase transitions, thermo and fluid dynamics, liquid-solid phases modelling, laser beam propagation and calculation of elastic linear stresses and distortions [1, 2, 3, 4]. For the beam propagation a ray casting algorithm was developed, which is able to deal with distributed partitioning of the domains for parallel computing. The simulation model is able to handle the transient dynamics of the processes and covers the time scale from nanoseconds to seconds [5, 6]. The free surface of the molten phase is treated by the Volume of Fluid method and expanded by an evaporation model.