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Additive manufacturing by fused filament fabrication provides an innovative manufacturing process for new design vision and complex geometry components. This study aims to establish the relationships between the process parameters and the mechanical properties of 3D printed parts using Taguchi design of experiment. The proposed method also enables the study of the filling orientation effects on the cohesion of the printed layers and the overall fracture behavior. We reviewed and optimized the effects of the critical parameters of process such as the layer thickness, the temperature, the print speed, and the filling orientation on Young's modulus and tensile strength. Then the effect of raster angle on the cohesion between the printed layers, as well as the failure modes were analyzed. The results show that the layer thickness and the filling angle are more influential on the mechanical properties. An analysis of the fracture surfaces of tensile specimens was also performed and it indicated a fracture following the filling direction. Furthermore, the fill angle 0/90° shows the best adhesion between the printed layers.

There is a growing need for 3D printing of polymer structures in a cost-effective way and green. This study presents an experimental approach to investigate structural parameters effects on mechanical properties of polylactic acid (PLA) hollow-sphere structures manufactured with fused deposition modeling (FDM). The mechanical behavior characteristics of square_hexagonal stacking, closed_open porosity and parallel_perpendicular compression direction compared to the direction of manufacture under quasi-static uniaxial compression are examined using Taguchi method. The S/N ratio analysis and the Analysis of Variance (ANOVA) were used to find the optimal parameters that improve the mechanical properties (Young modulus, yield strength) and to provide a significant ranking of the different parameters analyzed in this paper. It was found that the optimum level and significance of each process parameter vary for “hexagonal cells,” “open porosity” and “parallel direction.” The optimal values of the results give a Young modulus E of 90.12 MPa and a yield strength [Formula: see text] of 3 MPa. Furthermore, the experimental results further reveal that the porous structure with the loading direction that is parallel to the direction of manufacture, has a higher strength and a progressive collapse of the cells to those with a perpendicular direction.

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