On the measurement of the coupling loss factor of structural connections

Abstract

Previous attempts to measure the coupling loss factor of structural joints have shown that the results are very sensitive to small errors in the measurements. As the energy transfer at the joints is usually smaller than the dissipation loss in a structural member. the direct measurement of the coupling loss factor is very difficult. In this paper a development of the in situ measurement method used by Bies and Hamid is described. An iteration technique is used to give estimates of the coupling loss factor and individual dissipation loss factors which provide the best fit to the experimental data. Results for a simple two plate configuration compare well with theory for the coupling loss and independent measurements for the dissipation loss factors. The method is then applied to the junction of a plate and cylinder where the coupling loss is somewhat lower than that of the two plate junction.