Influence of infill properties on flexural rigidity of 3D-printed structural members

This paper characterises the flexural properties of relatively slender structural members (beams) manufactured using a FDM-based 3D printer. The primary goal is to assess the influence of infill properties on flexural rigidity through a parametric investigation. Infill percentage, infill orientation, and member thickness provided the parametric variation. The beams were tested by three-point bending, free vibration, and buckling. The tests showed that flexural rigidity varied linearly with infill percentage over most of the range considered, but fell off quickly below 10% infill. The optimal infill percentage that maximised specific flexural rigidity (flexural rigidity to length density) of the beams was determined to be between 10% and 20%.