Influência dos núcleos honeycombs hexagonal, auxético e híbrido a base de petg e pla em compósitos sanduíche utilizando sisal-epóxi

Abstract

In this work, the making of sandwich panels was elaborated. In total, six panels were produced with different characteristics in relation to the core and the type of material used, which in the future will become the test specimens of the experiment carried out. In summary, a sandwich panel is a structure made up of two faces and a core in the middle of these and its main objective is to provide a structure with good mechanical properties, mainly in relation to its flexural rigidity, having a low density. Starting from this point, for the faces, a composite made of epoxy resin and sisal was used. And for the cores, honeycombs of different configurations were used, made of PETG and PLA in the 3D printer. Sisal is a plant grown in semi-arid regions and is used for commercial purposes, with the states of Bahia and Paraíba, in Brazil, being the main producers. Sisal fiber is compared to fiberglass in terms of strength and stiffness, but it is cheaper. In addition, sisal fiber is non-toxic and does not irritate the worker's skin. All of these factors make sisal one of the most studied plant fibers. Three types of different configurations of honeycombs were used, namely hexagonal, auxetic and hybrid. The honeycombs cores, aim to support the faces of the sandwich structure, their arrangements based on biomimetics, make them a material of high mechanical properties and low density. Along with these nuclei, their behavior in PETG and PLA materials was also tested. The PETG material performed better when compared to PLA, with the exception of the hexagonal PETG honeycomb. The best performing honeycomb of the PETG material had 8.87% more than the best performing PLA. As for the structures of the cores, the ones that fared better were the cores with auxetic structural configurations for PETG and hybrid for PLA.