Effect of build orientation on the mechanical reliability of 3D printed ABS

Increasing use of 3D printing techniques to manufacture consumer products and open-source designs raises the question of “What is the mechanical reliability of 3D printed parts?” Therefore, the purpose of this paper is to investigate the impacts of build orientation on the mechanical reliability of acrylonitrile butadiene styrene (ABS) produced using 3D printing.

Tensile tests on ABS specimens were performed with and without a hole in the center, which were produced by fused deposition modeling (FDM). Seven sets of approximately 30 specimens were printed in XY, XZ and C+45 orientations to obtain reliable fracture statistics. Weibull analysis was performed to quantify the variation in the tensile strength.

The Weibull analysis showed that the reliability of FDM produced ABS can be as low as advanced ceramics. Weibull moduli of specimens without a hole were between 26 and 69, and specimens with a hole had Weibull moduli between 30 and 41. P-type deviations from the Weibull statistics were observed. The XZ orientation resulted in the highest average fracture strength for specimens with and without a hole, and C+45 orientation resulted in the lowest strength.

As the Weibull distribution relates the applied stress to probability of failure, the Weibull analysis provides a practical design criterion to achieve specific reliability levels for additively manufactured parts.

This study, for the first time, provides Weibull statistics for FDM-produced ABS parts, which can be used to predict mechanical reliability.