Damping characterisation for 3D-printed polymeric structure with different geometric parameters

This paper presents an experimental investigation into the influence of infill patterns and geometric angles on the damping properties of polymeric structures fabricated using fused deposition modelling (FDM). It quantitatively modelled the impact of geometric attributes of infill patterns on structural damping behaviours for the first time. The application of FDM highlights the ability to artificially control material damping without changing structural dimensions. Therefore, it has the potential to be used to fabricate customised polymer structures for energy absorption and vibration suppression applications. In the presented research, impact tests were conducted to assess the fundamental damping ratios of 3D-printed Polylactic acid (PLA) cantilever beams featuring various infill patterns (grid, triangle, and hexagon) and geometric angles. Notably, the triangle infill pattern with a filament angle of 60° exhibited the highest damping ratio, reaching up to 0.0163. Furthermore, an empirical model was developed and validated to establish a relationship between infill angles and fundamental damping ratios. The grid and hexagon patterns demonstrated promising results during the model validation phase.