TENSILE PERFORMANCE OF NON-PREFERENTIAL INFILL ARCHITECTURES IN FDM-MANUFACTURED ABS

Resumen

Fused deposition modeling (FDM) additive manufacturing has expanded its use in engineering applications because of its geometric flexibility, relatively low cost, and capacity for decentralized fabrication of polymeric components. However, the layer-by-layer nature of the process introduces mechanical anisotropy, particularly associated with raster orientation and interfacial bonding between adjacent deposited roads. This study evaluates the effect of non-preferential infill patterns on the mechanical performance of acrylonitrile butadiene styrene (ABS) specimens manufactured by FDM. Specimens with geometry based on the ASTM D638 Type I configuration were fabricated using four infill strategies: raster lines parallel to the tensile loading direction, raster lines perpendicular to the loading direction, Hilbert Curve, and Cross. The specimens were subjected to tensile testing in a universal testing machine, and ultimate tensile strength, yield strength, and strain were analyzed. The results showed that mechanical performance was strongly dependent on the deposition strategy. The parallel-line group presented the highest average ultimate tensile strength (23.46 MPa), closely followed by the Cross pattern (23.07 MPa), whereas the Hilbert Curve and perpendicular-line groups showed lower values, 14.64 MPa and 11.38 MPa, respectively. The Cross pattern reached 98.3% of the ultimate tensile strength obtained by the parallel reference group, indicating its potential to reduce the directional mechanical penalty typically observed in FDM without relying on favorable raster alignment. Non-preferential infill patterns may therefore represent a promising alternative for applications in which the predominant loading direction is unknown or variable, provided that the printing parameters are properly adjusted.