Study on the effect of thickness on sound absorption performance of foam aluminum

Abstract This paper investigates the effects of different thicknesses on the sound absorption performance of foam aluminum with different pore sizes through a combination of experiments and theoretical research. The results show that the average sound absorption coefficient of small-pore foam aluminum increases with increasing material thickness. As the thickness increases, there is a trend of the peak sound absorption performance shifting towards lower frequencies. In the mid-frequency range, although the sound absorption coefficient increases with the thickness of foam aluminum, the growth rate decreases. The average sound absorption coefficient of large-pore foam aluminum significantly increases with the material thickness and is reflected across various frequency ranges. With the increase in thickness, the sound absorption efficiency also improves, but the rate of improvement gradually slows down after reaching a certain thickness. Samples with the same thickness exhibit different performances in sound absorption coefficient, especially in frequencies above 2000Hz, where these differences are more pronounced. In the high-frequency range, the sound absorption coefficient of 100mm-thick large-pore foam aluminum material approaches 1, approximately 0.95.