Structure-borne sound transmission at floor/joist connections in wood frame buildings

Abstract

The overall sound transmission in wood frame buildings is largely affected by flanking transmission involving the structural members of the building. Due to the inhomogeneous and anisotropic nature of the building components, as well as the difficulty of modeling the structural connections, theoretical predictions of flanking transmission are characterized by a considerable uncertainty. This paper investigates structure-borne sound transmission at plate/beam junctions which are typical of floors in wood frame buildings. The aim of this study is to gain a better insight into the dynamic behavior of the floor assembly and to improve the accuracy of the theoretical predictions of vibrational energy flow through floors. For this purpose, measurements are carried out on a small floor section for various coupling conditions of the joists. By varying the number of fasteners used to attach the joist to the plate, frequency ranges are identified where the junction behaves as a line connection or as a series of local connections. The experimental results are compared to theoretical predictions using statistical energy analysis, where coupling loss factors are calculated based on the wave approach for semi-infinite plates.