Analysis and modelling of damage mechanism in FDM 3D-printed lattice structure under compression loading

Fused filament fabrication (FFF), commercially known as fused deposition modelling (FDM), is a widespread 3D printing process that builds up components by depositing a continuous filament of material, typically a thermoplastic, along a determined path. The mechanical performance of such parts is promising, even if strongly influenced by the deposition process. In this work, the mechanical behaviour of a specific lattice structure printed in acrylonitrile butadiene styrene (ABS) is studied and a model of lattice behaviour up to the damage regime is developed, with emphasis on the resulting anisotropy. The investigation starts with the analysis of the anisotropy of simple prismatic samples printed with various filament orientations. Deformation and damage of the lattice structure under compressive loading is observed at the meso- and micro-scales. An anisotropic model is then developed within the ABAQUS (c) environment to reproduce the elasto-plastic behaviour, incorporating onset and evolution of inter- and intra-layer damage. Good agreement is observed between the modelled and experimental response.