Digital volume correlation analysis of polylactic acid based fused filament fabrication printed composites

Fused filament fabrication (FFF) has rapidly begun to see implementation in industrial fields as a method of rapid manufacturing. Traditional FFF parts are made from a single thermoplastic polymer. The polymer is heated to its melting point and deposited on a work bed where a model is gradually built from the base up. While traditional FFF parts have low mechanical properties, a reinforcing phase allows for improved mechanical properties. The addition of a reinforcing material to the base polymer and complex internal microstructure of the 3 D printed party leads to anisotropic mechanical properties. Thus, these materials' mechanical properties become challenging to characterize using traditional measurement techniques due to the previously mentioned factors. Therefore, it is essential to develop a method in which mechanical properties can be measured and analyzed. This study aims to characterize the mechanical behaviour under a uniaxial tensile load of an FFF produced polylactic acid (PLA)-copper particulate composite. The internal response of the FFF sample was imaged using micro-computed tomography at predetermined loads. The mu-CT images were input into an open-source digital volume correlation (DVC) software to measure the internal displacements and strain tensor fields. The study results show the development of different strain fields and interior features of the FFF parts.

Automated summary

Fused filament fabrication (FFF) has been increasingly used in industrial fields as a method of rapid manufacturing, with the addition of reinforcing materials to improve mechanical properties posing challenges in characterization. A study aimed to develop a method to measure and analyze the mechanical properties of FFF produced materials, which exhibit anisotropic mechanical properties due to the complex internal structure and the added reinforcing phase. The study utilized micro-computed tomography and digital volume correlation (DVC) software to analyze strain fields and internal features of the FFF parts under uniaxial tensile load.