In this study, wood-based sandwich panels commonly used in interior applications were manufactured with core layers designed with different geometrically corrugated shapes, namely circular, rectangular, and trapezoidal. To determine the sound insulation performance of the produced sandwich panels for interior use, the sound absorption coefficient (α) and sound transmission loss (dB) values were measured using the impedance tube method. According to the obtained data, it was determined that the sound absorption coefficients and sound transmission loss values of the wood-based sandwich panels varied depending on the perforation ratio and depth applied to the panel surfaces, material type, core geometry, and frequency levels. According to the results of the experiments, it was determined that perforation applied to the panel surfaces had a positive effect on the sound absorption coefficients, that the sound absorption coefficient increased significantly as the hole depth increased, and similarly, the geometric corrugation applied to the core layer also improved the sound absorption coefficient. In addition, it was observed that an increase in frequency level resulted in an increase in the sound absorption coefficient. However, it was determined that the sound absorption coefficient of the fiberboard used on the surface was higher only at the 2000 Hz frequency level. Regarding the sound transmission loss values of the panels, it was determined that the perforation applied to the panel surfaces and the hole depth had a negative effect, whereas the core geometry had a positive effect, and the highest sound transmission loss occurred in the panel with a circular corrugated core. Moreover, the sound transmission loss of the panels was observed to increase with rising frequency. In conclusion, the application of perforations on the sandwich panels and the geometrically shaped corrugations in the core layers were found to enhance the sound insulation performance. Furthermore, in future similar studies, it is recommended to investigate in detail the effects of different angular values of the geometric corrugations applied to the core layer, as well as the perforation ratio, diameter, and depth.
Imirzi et al. (Tue,) studied this question.