Multi-scale process simulation for additive manufacturing through particle filled vat photopolymerization

The majority of research into vat photopolymerization (VP), has been focused on experimental investigations of the influence of process and material parameters. In a specific application of the VP technique, where the resin is filled with particles, this empirical approach has its limitations. In order to fully understand the relation between process parameters and the material properties a detailed numerical analysis is needed. In this paper we present a multi-scale and multi-physical simulation approach to unravel such relations in the complex production process. Using a homogenization approach, the influence of the filler particles, in this case alumina, on the light scattering, conversion characteristics and resulting effective thermal and mechanical properties is determined. The effective composite material and scattering properties are then used as input in a process simulation framework. This enables prediction of key filled-VP characteristics at a structural level. A mesh sensitivity analysis at the component scale reveals that adequate predictions may be obtained with a rather course discretization, facilitating multi-physics VP part simulations.