Multi-component power transmission from structure-borne sound sources into lightweight structures

Abstract

The power transmission between structure-borne sound sources and adjacent structures is generally of complex nature. For an accurate description the interaction between multiple contact points and several directional components must be taken into account. While calculation methods to predict the transmitted power are generally available, the main problem is the acquisition of extensive source and receiver data. This is especially true with regard to lightweight structures where source and receiver mobilities exhibit matched conditions and when rotational components of motion are involved. Therefore, the description needs to be simplified while at the same time a sufficient accuracy has to be retained. This work investigates the power transmission of a fan unit source that is mounted to a rib-stiffened aluminium plate at several contact points. Full data sets of source and receiver have been measured using a finite difference technique, including translational motion perpendicular to the structure as well as moment excitation around the in-plane axes of the plate. Both a rigid connection as well as a connection using resilient mounts are considered. Contributions of different components of motion are discussed and possible simplifications are deduced. © 2013 Acoustical Society of America.