Sandwich structures have high specific flexural stiffness, high energy absorption capacity, and superior heat and sound insulation properties. These features have become an essential 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. Significant advancements have been made in the utilization and production of auxetic structures and many other areas due to the advent of 3D printing technology, and the creation of these difficult-to-manufacture geometries is now feasible. Auxetic structures attract attention in terms of acoustic properties as well as their mechanical advantages. This study produced three-dimensional sandwich structures with two different auxetic core geometries printing using FDM (Fused Deposition Modeling) technology. Experiments were carried out with the impedance tube to examine the acoustic characteristics of the produced sandwich structures. The sound transmission losses (STL) and sound absorption coefficients (SAC) of sandwich constructions were experimentally measured using an impedance tube setup. The results 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.
Anahtar Kelimeler: Auxetic Materials, Sound Absorption, Sound Transmission Loss, Sandwich Materials