Scheck J., Fischer H., Gibbs B.

Measurement and prediction of the structure-borne powers from vibro-acoustic sources in buildings is an important task. It is in particular useful to evaluate the predominant components of excitation (forces and moments) since this can lead to simplifications in the representation by, for example, neglecting the least significant components. In the installed condition, direct measurement of the component powers is difficult or even impossible since it requires the installation of force transducers between the source and receiver. The registration of moments is particularly problematical. Using reciprocity principles, an indirect method is investigated that circumvents these difficulties. The reciprocal method was applied to investigate the power flow from a vibrating lightweight stair into a receiving wall through a single contact. The aim was to establish the predominant components of excitation and thus simplify the characterisation of the stair as structure-borne sound source by means of the contact free velocity and mobility.