Fatigue behavior analysis in reinforced PLA parts manufactured by FDM

Abstract

Fused Material Deposition Modelling (FDM) is one of the most extensive 3D printing processes. However, its integration and application to structural parts remain limited to some extent, due to the polymeric materials that can be processed, generally PLA and ABS. FDM printing involves a large number of manufacturing parameters, which can also influence the mechanical properties of the final part. Although the static mechanical properties of FDM components are well documented, the dynamic mechanical properties are not yet fully analyzed. Similarly, in the field of composite materials, reinforced thermoplastics are increasingly used in structural load-bearing applications due to its high specific strength and ease of processing. Therefore, it is necessary to focus on the reinforcement influence on the mechanical behavior of printed parts. The fatigue response of these materials is strongly influenced by the anisotropy of the properties, due to the orientation and composition of the reinforcement. It should be noted that, despite the fact that short-fiber or particlereinforced polymers generally fail in a macroscopically brittle manner, the underlying failure mechanisms are, nevertheless, not due to crack growth. Difficulty in correctly identifying underlying failure mechanisms, during material characterization, can lead to erroneous conclusions in service life predictions. Consequently, present work focuses on the reinforcement influence analysis on the fatigue behavior with PLA-based parts manufactured by FDM, showing how the fatigue behavior life worsen with short fiber and particle reinforcement.