Torra i Fernàndez È., Pompoli F.

This paper includes the measurement and modelling of the mechanical and sound absorbing properties of various types of aluminium foam which can be used for reducing the acoustic field in automotive applications. Al-foam samples of different densities and thicknesses and diverse size of the pores are tested. The bending stiffness measurement is carried out for aluminium foam beams and an equivalent model is found in order to characterize the mechanical properties of the material. Furthermore, a set of diverse techniques are used in order to determine the acoustic parameters of the aluminium foam samples in a plane wave tube. The Al-foam samples are tested with the covering foil at the surface which creates a typical configuration of closed cell material. However, the samples are also tested without this foil resulting in aluminium foam material with opened cells just at the surface. Finally, the cells are interconnected by creating holes between the adjacent pores. A comparison of the three different cases for the diverse properties is carried out.