Influence of void contour on the elastic behavior of parts produced by material extrusion

Abstract

The significant void content is the most noticeable flaw of 3D printed thermoplastic structures. The voids run parallel to the printed filaments, resulting in non-ellipsoidal geometries that are directly related to the printing variables. Until recently, only numerical solutions for accurate simulation of void geometry have been published, while analytical models have been limited to solutions of ideal geometries such as long cylinders. The impact of the geometry of void inclusions on the elastic behavior of acrylonitrile butadiene styrene (ABS) produced by material extrusion is examined in this study, and a unique semi-analytical method for real void geometries is proposed using, as basis, finite element (FE) solutions of Eshelby’s tensor. The FE solutions of Eshelby’s tensor are obtained by employing the FE approach to solve the elasticity problem of a large matrix containing one void inclusion. The numerical solutions are then used to evaluate the effective elastic properties using the effective field methods. The results of the semi-analytical method are in good agreement with numerical and experimental results.