Sound Insulation Property of Aluminum Foam Sandwich Panel and Its Optimization

A sound insulation prediction model of the aluminum foam sandwich panel was established on the basis of statistical energy analysis method, and verified by experiments. The effects of density and thickness of the aluminum foam on sound insulation property of the sandwich panel were predicted by the model. The acoustic vibration characteristics of the sandwich panel were analyzed. The sound insulation property of the sandwich panel was optimized by installation of damping layer. The results show that with the density of the aluminum foam increasing, the sound reduction index of the aluminum foam sandwich panel had relatively large increase amplitudes at low and medium frequencies and relatively small increase amplitudes at high frequencies. With the thickness of the aluminum foam increasing, the sound reduction index had relatively large increase amplitudes at medium frequencies and relatirely small increase amplitudes at low and high frequencies. The weighted sound reduction index increased with the density or the thickness of the aluminum foam increasing, but the increase amplitude decreased. When a 0.8 mm thick damping layer was placed in the middle of the aluminum foam, the weighted sound reduction index was effectively improved by 2.8 dB.