Mechanical strength optimisation of additively manufactured parts has been attracting attention in recent years.

The technique can expand manufacturing capabilities of polymer parts with improved mechanical strength. However, the mechanical properties of these need to be controlled when compared to those manufactured with conventional methods (e.g., injection moulding).

In this work four key process parameters, are investigated for their effects on Ultimate Tensile Strength (UTS) of a specimen made of Polylactic acid (PLA) with an open-source 3D printer, namely: print position, raster angle, layer thickness and air gap. for reliability and robustness.

The investigation employs experiments together with the statistical methodologies of Taguchi and Analysis of Variance (ANOVA) to identify significant parameters.

Attention has been given to specimen alignment during tensile strength testing and the experimental procedure due to the orthotropic nature of additive manufacturing. The experimental results are used as a knowledge base for a Fuzzy Logic system to identify the optimum setup for highest UTS.

Finally, predictions and validation run for the selected parameters are conducted and a comparison between these methods is made.

Results show an 85.29% agreement in predicting UTS through Taguchi, while when focusing on the most significant parameter of print position the prediction reaches 93.66% agreement compared to experimental values

This article is shared by Nikolaos E. Statheas, Andreas -Marios Tsainis, Constantinos Stergiou Achilles Vairisd