Evaluating Mechanical Properties and Failure Mechanisms of Fused Deposition Modeling Acrylonitrile Butadiene Styrene Parts

This paper presents a comprehensive experimental study in exploring the influence of key printing parameters on mechanical properties and failure mechanisms of acrylonitrile butadiene styrene (ABS) material. Three parameters with three levels-layer thickness (0.09 mm, 0.19 mm, and 0.39 mm), printing plane (XY, YZ, and ZX), and printing orientation (horizontal, diagonal, and vertical)-are considered, which form an L-27 experimental design. Following L-27, tensile and compressive specimens are fabricated and tested. Young's modulus, yield strength, failure strength, and strain of specimens are measured, evaluated, and compared with their injection-molded counterparts. Experimental results indicate that tensile specimens with a layer thickness of 0.09mm and printing plane orientation of YZ-H reveal the highest stiffness and failure strength. While injection-molded specimen shows the highest yield strength, ductility of printed specimens is 1.45 times larger than that of injection-molded part. YZ along with XY specimens shows a neat and clean standard fracture failure at 45 deg, where the layers reorient themselves followed by stretching before fracture failure, thus providing sufficient ductility as opposed to ZX specimens, which fail along the direction perpendicular to the loading. Compressive XYH and XY-D specimens have the highest stiffness and yield strength, and failure mechanisms involve initial compression followed by squeezing of layers leading to compactness followed by breakage due to tearing off or fracture of layers. The findings imply that anisotropy of fused deposition modeling (FDM) parts cannot be avoided and hence the appropriate parameters must be chosen, which satisfy the intended properties of the material subject to specific loading scenario.