Experimental round-robin evaluation of structure-borne sound source force-power test methods

The determination of the structure-borne noise from operational equipment in airplanes is a complex process that requires much source and receiver component information in the analysis. Different test setups and instrumentation usually are required to obtain these quantities separately; for example, free velocity, blocked force, source and receiver mobilities, isolator properties and transmitted power. A previously proposed approach, combining the inverse force method (IFM) and the reception plate method (RPM), and enabling dual force-power measurement from a single test platform, was demonstrated in laboratory tests. This paper reports on the measurement variations of blocked force and transmitted power from the integrated test setup. To gauge the practicality and readiness of the test methods, an experimental round-robin evaluation was arranged and coordinated with four industrial participants. The same source was used in the round robin evaluation with controlled mounting details, in order to investigate the source installation sensitivity. In general, good agreements were observed between powers obtained by the two methods from data acquired at each test site; larger variations were observed in measurement across test sites. Work continues to determine the test method uncertainty; however, both test methods are considered acceptable and ready for wider industry applications.