On the damping loss factor of viscoelastic materials for naval applications

Viscoelastic materials are used in ship and yacht constructions for floating floors, engine foundations and laminated glass. The contribution of viscoelastic rubbers is related to their capability to withstand and damp airborne and structural borne noise. New regulations have outlined the necessity to perform numerical analysis in the early design stages, when modifications in the structural layout and/or in the insulation plan are more feasible and less expensive for shipyards. The determination of damping loss factor of viscoelastic materials is an open topic in vibro-acoustic engineering; the complexity of their mechanical characterisation could have consequences in terms of unreliable numerical simulations if not validated by experiments. In this paper, a new reliable and simple testing procedure for the determination of damping loss factor for viscoelastic materials is presented; experimental data have been compared with finite element analyses and statistical energy analyses in order to validate the proposed method.