Influence of meso-structure and chemical composition on FDM 3D-printed parts

We studied the influence of extruded filament dimensions and chemical composition on mechanical behavior of Fused Deposition Modeling (FDM) objects made of Acrylonitrile Butadiene Styrene (ABS) polymer. All aspects are investigated through experimental campaigns: we tested three different filament dimensions on the same material and two different chemical compositions with the same filament dimensions. We verified that FDM ABS specimens show anisotropic mechanical properties since they vary with filament extrusion direction. Accordingly, Classical Lamination Theory (CLT) and Tsai-Hill yielding criterion were found to be well capable of predicting in-plane stiffness and strength of FDM specimens. We assessed that, varying chemical composition and filament dimensions, it is possible to tune fiber properties and fiber-to-fiber bonding and, consequently, the overall mechanical properties at macro-scale, in particular the yielding strength and the strain at failure. The experimentally obtained data are useful to calibrate mechanical models to be used with computational tools as finite element analyses. (C) 2017 Elsevier Ltd. All rights reserved.