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.