Investigation on mechanical performances of various cellular structures produced with fused deposition modeling (FDM)

In this study, it was aimed to experimentally compare the mechanical properties of the traditional honeycomb structure, which is one of the cellular structures with its own specific area of use with its features such as lightness and load absorption, and the new generation re-entrant, chiral and hybrid structure (re-entrant + honeycomb) with negative Poisson behavior. In this context, standard test samples with honeycomb, re-entrant, chiral and hybrid structures were produced with fused deposition modelling (FDM) under optimum conditions by using PLA material and different geometric parameters. Tensile and compression tests, hardness tests and surface roughness measurements were carried out with the specimens that were additively manufactured. According to the results, it was determined that the direction of the unit cells in the cellular structure and the rib thickness affect the energy absorption properties of the cellular structures. While the tensile and compressive strengths of the cellular structures increased with increasing rib thickness, the average Ra value and hardness value were measured as 14 mu m and 75 Shore D respectively. Although negative Poisson ratio was observed depending on the amount of deformation in re-entrant, chiral and hybrid structures, positive Poisson behavior was observed in honeycomb structures.