Driving-point mobility and sound insulation of structured sheet metal

The study shows that the resulting driving-point mobility depends on frequency as well as on structure size. Additionally, it was found that the location of excitation has a notable impact on the resulting mobility spectra. The sound reduction index of the structured sheet metals is similar to that of a plane reference plate for low frequencies up to 4 kHz. In a range of medium frequencies between approximately 5 kHz and 12.5 kHz, the sound reduction index of the structured plates is clearly below that of the reference plate.