Bending beams: Effects of infill pattern and density on stiffness of 3D printed beams

Fused deposition modeling (FDM) is an additive manufacturing process that builds parts layer by layer, selectively depositing melted material in a predetermined path. Two of the principal 3D-print settings that can be modified with FDM are infill density and infill pattern. This project examined the impact of both of these settings on the stiffness of beams printed using FDM. To obtain stiffness values, an accelerometer connected to an oscilloscope was first attached to beams before flicking them in order to determine their resonant frequencies. These data points, along with length, thickness, and density measurements, were then used to calculate each beam's stiffness using Euler–Bernoulli beam theory. An analysis of the results showed that both infill density and infill pattern had a significant impact on the stiffness of beams, suggesting that these print settings are important factors to keep in mind when designing parts to be 3D-printed using FDM.