Photopolymerized AM materials: modelling of the printing process, mechanical behavior and sensitivity analysis

The physical-chemical processes involved in light-induced polymerization (photopolymerization) are widely exploited in Additive Manufacturing technologies such as Stereolithography and Digital Light Processing. The influence of the AM process parameters on the physical properties of manufactured components has been often investigated through empirical methods based on the trial and error approach, i.e. by collecting and interpreting a large amount of experimental data. However, when specific physical properties are required, accurate modelling of the liquid-solid conversion is necessary. In this work, in order to determine the properties of the resulting material according to the adopted process setup, we present a multi-physics approach to model the physical-chemical transformation taking place in photopolymerization. The role played on the final mechanical properties by the laser light intensity and by its moving speed is considered. Further, the influence of the uncertainty of the process parameters is investigated through a sensitivity analysis. The approach is suitable for investigating the reliability of additively manufactured components as well as for their design according to an optimum printing strategy. From the perspective of making innovative functional materials, the proposed multi-physics model allows tuning the printing process in order to get the desired distribution of mechanical properties.