Structure-borne sound transmission in wall-floor timber junctions with damping elastomers

Abstract: The wooden multi-storey building industry is facing persistent sound transmission problems at low frequencies. Inserting elastomers within wall-floor junctions is common usage nevertheless no accurate studies have elucidated the real behavior of those nonlinear combined materials yet. Deeper knowledge is needed to create a relevant FE model which will help industry to use those materials efficiently.The nonlinear dynamic behavior of the elastomers inserted in wooden junctions is analyzed while the static load acting on them is varying. The specific situation where those elastomers were tested is a scaled room made of two walls and one floor.An experimental study was conducted on this prototype wooden construction and a numerical analysis was performed on the Finite Element model of it. The frequency response functions of several positions were measured on the physical setup.The study showed that loaded structures (up to 2 times the load of the floor) had a lower damping ratio. Having the structure standing on really stiff or elastic material does not differ when comparing experimental and analytical modal parameters.Those results depict the behavior of elastomers for different load cases and are definitely a step forward for the conception of a reliable FE model.