Effect of support legs of dry-type double floor structures on heavy-weight impact sound reduction performance using a rubber ball impact source

Dry-type double floor structures are widely used in Japan as floor finishing systems for residential buildings, but they can increase heavy-weight impact sound. However, the influence of the installation conditions of support legs on the heavy-weight floor impact sound reduction performance of double floor structures has not yet been sufficiently investigated. In this study, the nonlinear effects of support legs arising from their contact conditions were examined through numerical simulations. First, a sectional model experiment and a corresponding numerical study were conducted to investigate the transfer force characteristics of double floor structures, demonstrating the importance of modeling the installation conditions when calculating the frequency characteristics of the transfer force. Then, a parametric study was carried out on the heavy-weight impact sound reduction performance of double floor structures. The results revealed that the nonlinearity of the support legs exerts a strong influence on the reduction performance, indicating that the installation conditions of the support legs must be considered as a design factor in double floor structures.