Elastic Wave Transmission between Walls in Framed Buildings

The majority of framed buildings have joints between walls with a column running along the joint. Recent work has identified the importance of the column which generally reduces sound transmission between walls at high frequencies. In this work the effects of incident longitudinal or transverse waves as well as flexural waves at a joint with a column is studied together with the effects of an eccentricity. For incident flexural waves the importance of deformation of a column cross section due to shear forces on connected plates has been identified. In this work all of these properties are considered and effects on predicted sound transmission through framed buildings are demonstrated for each of the three wave types.

Solutions for transmission coefficients for bending, longitudinal and transverse shear waves at inline, corner cross and tee joints are obtained. The results satisfy reciprocity conditions. It is important to know what properties of the column have greatest effect on transmission so that the overall performance of buildings can be improved. The effects of varying the column cross section, materials properties and eccentricity are studied. Of these, variations in column dimensions produce the largest changes in transmission while typical variations in material properties and eccentricity are not important.