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

Abstract

Purpose 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. Design/methodology/approach 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. Findings 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. Practical implications 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. Originality/value This study, for the first time, provides Weibull statistics for FDM-produced ABS parts, which can be used to predict mechanical reliability.

The Effect of Porosity on Mechanical Properties of Fused Deposition Manufactured Polymers and Composites

“…The reliability of the 80 % infill seems to be correlated to the large distribution of density, as shown in Figure 2b. In our previous study, we reported similar and values for short carbon-fiber composite samples at the same infill parameter settings [18,37,38]. The strain at fracture m value was much lower than previous carbon-fiber composite results.…”

“…Recent work has shown that FDM produces parts with lower mechanical reliability than their subtractive manufactured counterparts [18]. These part-to-part variations can pose harm to consumers using FDM for load-bearing applications.…”

“…Analyzing mechanical reliability using Weibull statistics [17] is a common practice in ceramic AM literature [25][26][27][28] due to high variability in fracture stress. Although Weibull statistics are not commonly used for polymers, the author recently showed that the variation in FDMed ABS-dense materials can be as high as ceramics [29]. There are currently no reports on the mechanical reliability of AMed short carbon-fiber reinforced acrylonitrile butadiene styrene (SCFR-ABS) composites.…”

“…Error bars correspond to a 90 % confidence interval. Yellow represents moduli of FDMed ABS built in different orientations [18]. Gray represents experimental moduli of various porous ceramics [72].…”

Development of a Method of Additive Manufacturing by Material Extrusion Along Three-Dimensional Curves

“…This presents a discontinuity in the design process, since manufacturing parameters are applied after strength predictions are made, implying that stress analyses are unreliable unless the numerous parameters applied in the slicing and toolpath generation phase have been considered upstream in the stress-analysis phase [17]. The gap in the process chain between stress analysis and the assignment of manufacturing parameters is a factor that significantly limits the reliability of (particularly) FDM 3D printing methods for the production of end-use components [18]. A method of AM where toolpaths are generated directly based on stress analysis could, to a large extent, remove this discontinuity.…”