A vibroacoustic numerical method employing a finite-difference time-domain (FDTD) method, in which the target floor structure consisting a floor panel supported by support legs on a floor slab was modeled as a composition of two-dimensional plate elements for the double plate structure and one-dimensional bar elements for the support legs, was adopted to predict the vibroacoustic transmission characteristics through double-plate floor structure. In addition, by using the coupling method of the abovementioned FDTD and the DEM (discrete-element method), the damping effect of the floor structure by using granular materials set on the floor panels was estimated. In this paper, the basic theory of the FDTD scheme was validated through comparison with excitation test on an acrylic scale model, and the applicability of the method to prediction of the damping effect of the floor structure caused by granular materials was discussed through a numerical case study.
