Pseudo-forces methodology to be used in characterization of structure-borne sound sources

In the analysis of machinery noise generation and transmission the aspect of sound source characterization is of importance. Unlike for airborne sources, no widely applicable and practical methods are available yet for structure-borne sound sources. This paper presents the `pseudo-forces' methodology. In this approach the internal excitation in a source component is reproduced by fictitious forces on the outer surface. This method is intended to be applied for `compact' sources and in situations where (prototype) machinery is available for measurements. On the one hand this method respects the complex coupling of source component and mounting structure and on the other hand aims at reducing measurement effort. Experiments have shown the practicability of the approach. An overview is presented of an approach for characterizing structure-borne sound sources, which is called the pseudo-forces method. The method respects the interaction between source and mounting structure, but aims at simplifying the measurement and analytical effort involved. The underlying theory is outlined, as are the objectives and assumptions for the method. All governing numerical equations are provided, and application examples are presented as illustration