Mechanical properties of 3D printed polylactic acid elements: Experimental and numerical insights

The mechanical behaviour of polylactic acid (PLA) samples printed via material extrusion is experimentally and numerically addressed. An experimental program comprising tensile and three-point bending tests is carried out. Some filament printing orientations and different values of flow rate percentage are considered and their influence on the mechanical performance is investigated. From a numerical point of view, a new two-level model for the multiscale analysis is considered. The macroscopic structural behaviour of the 3D printed component is described with a laminate finite element model based on the first-order shear deformation theory. Each layer of the laminate is described with an elasto-plastic constitutive law and the geometrical and mechanical properties are derived from the experimental results. The micromechanical analysis is conducted only when inelastic strain occurs performing a non-linear analytical homogenization technique based on the Transformation Field Analysis. The obtained numerical results are compared with the experimental results highlighting the effectiveness of the proposed modelling approach.