A classification of materials more employed in applications related with vibro-acoustic problems is showed:
Materials with linear Elastic behaviour: In vibro-acoustics problems it is worked in small deformation domain, so that metallic materials is supposed to have a linear behaviour.
Visco-Elastics Materials : Pseudo-elastic materials are materials which have damping losses. Behaviour of plastics materials, rubber, closed cell foams could be explained with this model.
Porous Materials: They are materials which could have a structural behaviour similar to visco-elastics materials or be completely stiff. But they have a fluid phase in their interior interacting with solid phase and modifying the characteristic properties of material.
Elastics Porous Materials: It is a particular case of previous materials, in which solid phase has a elastic deformable behaviour, that allows possible couplings between fluid and solid phase.