9th INTERNATIONAL CONGRESS ON ENGINEERING, ARCHITECTURE AND DESIGN, İstanbul, Turkey, 14 - 16 May 2022, vol.1, pp.1-11
Sandwich structures are structures with high specific flexural stiffness, high energy absorption capacity, and superior heat and sound insulation properties. Due to these features, they have become an important subject in the increasing number of automotive weight reduction studies in recent years. In sandwich structures, the core material and geometry determine the main characteristic of the structure. Auxetic structures with Negative Poisson's Ratio (NPR) are core geometries that exhibit high mechanical properties but are difficult to manufacture. With the development of 3D production technologies, important developments have been experienced in the use and production of auxetic structures, as in many areas, and the production of these difficult to produce geometries has become possible. Auxetic structures attract attention in terms of acoustic properties as well as their mechanical advantages. In this study, three-dimensional sandwich structures with two different auxetic core geometries were produced with Fused Deposition Method (FDM) technology. Experiments were carried out with the impedance tube to examine the acoustic characteristics of the produced sandwich structures. The Sound Transmission Losses (TL) and Sound Absorption Coefficients (SAC) of the sandwich structures were experimentally measured with the impedance tube setup. The results obtained show that sandwich structures with two different auxetic cores have different STL and SAC values in different frequency ranges, and it has been revealed that there are differences and superiorities in usage areas depending on these values.