Experimental and theoretical study on transfer force characteristics of support legs of dry-type double floor system

The dry-type double floor system, which is popularly installed for apartment buildings in Japan, has a negative aspect that it generally causes deterioration of heavy-weight floor impact sound insulation. To predict the effect of the double floor, all the components of the vibro-acoustic system need to be modeled precisely. In this paper, an experimental and theoretical study is conducted to investigate the transfer force characteristics of support legs of the double floor. In the experiment, a small specimen with four support legs is impacted by the standard rubber ball, and the transfer force is measured under the legs, where changing the fall height of the impact source, the mass of upper flooring, the type and adhesive condition of support legs. A simple theoretical model is introduced for the double floor system, and the viscoelastic properties for support leg and rubber ball are estimated from the experimental results. Finally, this approach is validated by using a 2-DOF system, showing that it can well simulate the transfer force characteristics of support legs.