Effect of infill pattern and build orientation on mechanical properties of FDM printed parts: An experimental modal analysis approach

Fused Deposition Modeling (FDM) is one of the most widely explored additive manufacturing method that uses thermoplastic materials to manufacture products. Mechanical properties of parts manufactured using FDM are influenced by different process parameters involved during manufacturing as they impact the bonding among different layers of cross-section. In this study, the effect of infill patterns and build orientations on the mechanical properties of PLA based parts manufactured using FDM method is studied. Six different infill patterns (triangles, cubic, concentric, tetrahedral, lines, and zigzag) and three different orientations (flatwise, edgewise, and upright) are considered for rectangular beam type parts. For determining mechanical properties of parts with different infill patterns and orientations, flexural bending test is performed. Experimental modal analysis of manufactured parts is performed to observe the relation of natural frequencies with elastic modulus of the parts obtained from flexural bending test. The possibility of experimental modal analysis as an alternative non-destructive method for testing mechanical properties of FDM 3D printed parts is explored.