Impact Behavior Analysis of 3-D Printed Honeycomb Structures

The purpose of this paper is to evaluate the behaviour of 3D printed honeycomb structures under low velocity impact loading for their use in energy absorption applications. Additive manufacturing technologies are part of a growing field that represents high interest for industries such as aerospace, automotive and naval. This paper aims to determine the mechanical properties of a 3D printed polymer - Polylactic Acid (PLA) manufactured by FDM (Fused Deposition Modelling) technology. In this regard, first the material is characterized by low velocity impact dynamic experimental tests. A finite Element Analysis (FEA) is performed in LS-Dyna software in order to validate the results. The samples were manufactured by varying the infill percent to investigate the influence of different parameters on a batch of samples for every configuration. The 3D CAD modelling for impact tests samples were performed in Catia V5. Among wide range of cellular structures, honeycomb non-auxetic hexagonal cell pattern was selected in this study, assuring high strength/weight ratio. The amount of energy absorbed during the impact, the failure and degradation of the impacted specimens were monitored, following the analysis of experimental and numerical data. A fair agreement was obtained between experimental and numerical results, showing that honeycomb developed lightweight structures exhibits a proper energy absorption capacity, with a mechanism of release similar to metal or composite materials honeycombs.