Combined RVE-Cohesive elements approach to the multi-scale modelling of FDM 3D-printed components

Mechanical strength of 3D-printed components dramatically depends on printing process parameters. These can be usually set over a relatively wide range, in combinations that determine the microstructure morphology and the resulting mechanical behaviour. The present investigation focuses on the relationship between revealed structure and resulting mechanical properties of FDM-printed ABS specimens. The peculiar structures, examined at the meso- and microscale, are modelled by a finite-element Representative Volume Element (RVE) approach, in conjunction with cohesive elements to reproduce the sealing efficiency between fused filaments. The simulation of the tensile response up to failure falls within the 95% of confidence with experiments. Also, homogenized response of RVE determines spatial material constants useful for the effective numerical simulations of functional components, and intra- and inter-layer damage mechanisms are distinguished providing hints for the structural optimization.