Structure-Borne Sound Transmission from Machines in Buildings, Part 1: Indirect Measurement of Force at the Machine-Receiver Interface of a Single and Multi-Point Connected System by a Reciprocal Method

The analysis of structure-borne sound transmission is obscured by the complicated nature of the dynamic interaction between source and receiver at each contact point. There is little measured data because of the practical difficulties in directly measuring forces and moments at the contacts. This is particularly so in the case of moments, since there is not yet available an accepted method of registration. Even in the case of forces, where commercially transducers are available, it is seldom practical to insert transducers between the source and receiver without altering the installed condition. A method is described whereby the force and moment induced powers from an installed machine are measured indirectly by a reciprocal method. In the companion paper, the validated method is used to measure the moment induced power produced by a base sub-assembly. Hence, the relative importance of force and moment with respect to variation in machine excitation position on a receiving structure is examined.