Quasi-static Properties of a Bio-Based Sandwich Structure with an Auxetic Core
Résumé
Auxetic structure became the center of attention in the recent years because of their abnormal properties such as negative Poisson’s ratios. These materials exhibited many benefits like strength, higher stiffness and energy absorption, in comparison with conventional ones. This article presents the mechanical characterization of a bio-based sandwich structure with an auxetic core. The structure has been manufactured using additive manufacturing (3D printing technology). The core and the skins are made from the same biological material which is the polylactic acid. Thus, the sandwich structure is 100% bio based which makes it recyclable. Different density of the auxetic structure was studied in order to evaluate their influence on the mechanical properties of the sandwich. Uniaxial loading was performed on the skins in order to obtain the mechanical properties of the materials and on the core to obtain the Poisson’s ratios. Then, the sandwiches were tested in three points bending. The flexural and shear rigidity were measured for each beam. The results obtained showed that the auxetic core density plays a major role on the mechanical characteristic of the sandwich structure.