Numerical and experimental investigations on the acoustic power radiated by Aluminium Foam Sandwich panels

Aluminium Foam Sandwich (AFS) panels are a new class of flat structures, constituted by two aluminium layers with a core made by foamed aluminium. Their excellent combination of properties, arising from the metallic nature of the matrix and from the porosity behaviour of the foam core, guarantees high specific stiffness, thermal and acoustical isolation, as well as vibration damping. For these reasons, they are becoming more and more attractive in transportation engineering applications. In this work, numerical and experimental investigations on the acoustic power, radiated by Aluminium Foam Sandwich panels, are carried out. Two different Alulight® specimens, made of the same material but with different thickness and percentage of foam density, are investigated. A Finite Element model is used to estimate the distribution of velocity over the panel surface and, then, the radiated acoustic power is calculated through the discrete formulation of the Rayleigh integral for flat radiators. The numerical model is validated by means of experimental tests, performed by using a sound intensity technique.