Mechanical Properties of 3D-Printing Polylactic Acid Parts subjected to Bending Stress and Fatigue Testing.

J Antonio Travieso-Rodriguez,Jordi Llumà,Ramon Jerez-Mesa,Giovanni Gomez-Gras,Oriol Traver-Ramos,Joan Josep Roa Rovira

doi:10.3390/ma12233859

J Antonio Travieso-Rodriguez, Jordi Llumà + Show 4 more

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https://doi.org/10.3390/ma12233859

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Abstract

This paper aims to analyse the mechanical properties response of polylactic acid (PLA) parts manufactured through fused filament fabrication. The influence of six manufacturing factors (layer height, filament width, fill density, layer orientation, printing velocity, and infill pattern) on the flexural resistance of PLA specimens is studied through an L27 Taguchi experimental array. Different geometries were tested on a four-point bending machine and on a rotating bending machine. From the first experimental phase, an optimal set of parameters deriving in the highest flexural resistance was determined. The results show that layer orientation is the most influential parameter, followed by layer height, filament width, and printing velocity, whereas the fill density and infill pattern show no significant influence. Finally, the fatigue fracture behaviour is evaluated and compared with that of previous studies’ results, in order to present a comprehensive study of the mechanical properties of the material under different kind of solicitations.

Highlights

Manufacturing through fused filament fabrication (FFF) or 3D-printing is a phenomenon that has drastically changed the way manufacturing is understood, mainly during the last decade [1]
An analysis of variance (ANOVA) was performed on the dataset included in the Taguchi experimental array, for each parameter that describes the mechanical behaviour of the evaluated specimens
The influence of the layer orientation, layer height, filament width, printing velocity, fill density, and The infillinfluence pattern on performance ofheight, polylactic acid (PLA) specimens was studied through a Taguchi of the flexural layer orientation, layer filament width, printing velocity, fill density, The following conclusions can be extracted: and infill pattern on the flexural performance of PLA specimens was studied through a Taguchi design of experiments (DOE)

Summary

Introduction

Manufacturing through fused filament fabrication (FFF) or 3D-printing is a phenomenon that has drastically changed the way manufacturing is understood, mainly during the last decade [1]. Regardless of the rapid expansion of AM, the problem related to the identification and prediction of the mechanical behaviour and physical characteristics of the final pieces has been the main handicap for its application in industrial environments or final pieces. This difficulty lies in the fact that the parameters to be defined during the manufacturing process are numerous and interact with one another; and, on the other hand, because of the anisotropy of the material, caused by the high influence. Materials 2019, 12, x FOR PEER REVIEW of the filament orientations the manufacturing space [3]. Anisotropy originated originated thanks to thein difference between the bonding forces between strands ofalso the same layer thanks to the difference between the bonding forces between strands of the same layer (intralayer)

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