Stochastic modeling of the elastic response of parts produced by material extrusion using ideal voids

The voids in 3D printed materials produced by the material extrusion technique are mainly located between the printed filaments. Their shape depends on material and printing parameters and can be both convex and concave. This shape influences the accuracy of the predictions of common homogenization schemes that consider spheroidal shapes. A novel approach is introduced in this study for converting real voids to ideal supercylindrical ones that approximate better the shape of voids and can be described using only one parameter. This fact leads to a fast implementation in stochastic modeling schemes where fewer samples are required. The novel approach is implemented using the polynomial chaos expansion technique to predict the elastic properties of acrylonitrile butadiene styrene. The results are compared with previously performed tensile tests and both simple and computationally intensive models to provide a holistic understanding of the advantages of the new approach.