Comprehensive characterization of mechanical and physical properties of PLA structures printed by FFF-3D-printing process in different directions

The industrial interest in additive manufacturing (AM) techniques is currently increasing for the realization of functional mechanical components. For this reason, the structural simulation of parts or complete structures made using this new manufacturing technique is gaining considerable importance. To realise accurate finite element models for the purpose of predicting the dynamic or static behaviour of the component printed and avoid unexpected failures, it is necessary to be aware of some mechanical and physical properties of the print material. Unfortunately, in the literature, it is very difficult to find all the data necessary to perform static or dynamic simulations of 3D printed parts. In this context, this activity aims to determine all these mechanical and physical properties for parts made in White-Pearl Polylactic-acid (PLA) Ultimaker filament using the Fused Filament Fabrication (FFF) technique. A set of printing parameters was chosen and kept constant in all tests which, based on literature data, maximizes the static strength and the fatigue limit of the component. Only the building direction was varied to increase the applicability of the obtained results to any geometry. The main results found for the horizontally moulded specimens (representing the best constructive solution) are the Ultimate Tensile Strength equal to 57.15 MPa, the elastic modulus 2606 MPa, the fatigue limit evaluated at 2 × 10 6 cycles equal to 13.5 MPa, the damping and density of the material of 0.008 dimensionless value and 1.1246 g/cm3, respectively. Only thanks to the obtained results, finite element models can be developed for reliable static and dynamic analysis