Prediction of vibroacoustic transmission characteristics through double-plate floor structures by using finite-difference time-domain analysis

A vibroacoustic numerical method employing a finite-difference time-domain (FDTD) method, in which the target floor structure consisting of a floor panel supported by support legs on a floor slab is modeled as a composition of two-dimensional plate elements for the double plate structure and one-dimensional bar elements for the support legs, is proposed. While floor impact sound is difficult to accurately predict owing to the complexity of the vibroacoustic mechanism influenced by the coupling phenomena with the vibration of the double-plate structure connected by support legs and the sandwiched air layer between the double plates. In this paper, the basic theory of the proposed numerical scheme was validated through comparison with excitation test on an acrylic scale model, and the applicability of the method to a practical case of a vibroacoustic transmission via a two-layered floor structure was discussed through a numerical case study.