Effect of wall thickness and openings on the flexural properties of PLA produced by additive manufacturing

In this study, flexural performance of PLA samples produced by fused deposition modeling (FDM) was evaluated by experimentally and FEM analysis. For this purpose, test samples were manufactured by FDM using PLA filaments. Bending tests were performed on test samples with different wall thicknesses (2 mm, 2.6 mm, 2.7 mm, 3.8 mm, and 4 mm) and openings (1 space, 2 spaces, and 3 spaces). The results show that increasing wall thickness from 2 to 4 mm at constant openings can improve peak load capacity up to 170%. 118% peak load increase is achieved by increasing the number of openings from 1 to 3 at constant wall thickness. Within the scope of this investigation, ABAQUS software is utilized to carry out a Finite Element (FE) simulation to investigate failure mechanisms. Consequently, the simulation yielded deflection and force values that are consistent with the experimental findings. Furthermore, the structural characteristics were examined using TGA, XRD and SEM investigations. The PLA sample’s thermogravimetric analysis (TGA) curve indicated no mass loss up to 250–280 °C. Thermal combustion of polymer chains caused mass loss at 280 °C. The SEM data show that the sample contains secondary phase particles scattered throughout the matrix rather than a totally homogenous polymer structure.