3D Printed Cellular Structure Materials Under Impact and Compressive Loading

Abstract

Abstract Advances in field of lattice structure design has become possible mainly due to the emerging capabilities of additive manufacturing (AM) or 3D printing. Lattices have the potential to reduce solid volumes, giving advantages such as weight reduction, decreased part production cost and ability to absorb energy under compressive and impact loading. These materials are anisotropic due to structural geometry and the additive nature of 3D-printed layers, which stack mainly in Normal or Lateral direction to the applied load. In this study 3D printed materials were fabricated that are nearly isotropic and are also lighter than base material. The lattice structure was formed using strut-based cell topologies that are adjoined as tetrahedrons. Two different tetrahedron density specimens were produced with Acrylonitrile Butadiene Styrene (ABS) using a Fusion Deposition Modelling (FDM) printer. The fabricated specimens were then tested for impact and compression capabilities. For comparison purposes, solid specimens with the same overall dimensions and highest infill ratio were also produced and tested. After compression and impact testing, results indicated that solid specimens’ impact energy absorption is higher with lateral stacking order relative to load, and compression resistance is higher for normal stacking order. The tetrahedron-filled specimens exhibited minimal stacking directional dependency and the higher count tetrahedron specimens provided more impact energy absorption and more resistance to compression than the lower count one. The normalization of specimens with respect to their weight indicated high density tetrahedron specimens’ impact energy absorption is nearly equal to that of solid specimens’. These results are initial steps in creating lattice structured materials that are isotropic, lighter and stronger than the base material.