Investigation on the mechanical behaviour of 3-D printed lattice sandwich structures

Abstract

Cellular lattice structures have been gaining traction because of its fairly low mass and density, high stiffness, decent energy absorption capabilities and thermal and acoustic insulation. These unique characteristics and multifunctional advantages have enabled lattice structures to be preferred as the cores of sandwich panels over its counterparts such as foams and honeycombs, and significantly amplified their usage in engineering applications for a variety of fields, such as automobile, aerospace and bioengineering. A number of manufacturing methods are capable of fabricating cellular lattice structures. However, recent advancements in additive manufacturing have allowed for the fabrication of sophisticated designs and geometries of cellular lattice structures to a significantly high level of accuracy. This paper focuses on the comparison of mechanical properties of two 3-D printed cellular lattice structures, the Body- Centered-Cubic (BCC) and the 3-D Kagome. The selected lattice structures were designed in two configurations each to study on the effect of relative density on mechanical properties. Six specimens per design configuration (total of 24) were fabricated using the Projet 5500X 3-D Printer. Tensile test was conducted to evaluate the Young’s Modulus of the composite material, and compression test was conducted to determine the compressive response of each configuration. Both the ultimate compressive strength and compressive modulus of each configuration were normalized with the average mass of the specimens to improve accuracy, and the normalized data was analyzed. The 3-D Kagome was found to be a stiffer structure, whereas the BCC was found to exhibit better energy absorption characteristics. The findings concluded from this paper aim to create a better understanding of the selected cellular lattice structures, and also provide recommendations for future work on 3-D printed cellular lattice structures.