Audio frequency vibrations from machinery installations often result in noise problems caused by transmission of vibrations to connected structures and associated sound radiation from vibrating panels, etc. In practice, predictions based on energy methods such as statistical energy analysis (SEA) are mostly used for estimating the relative energy distributions of structures subject to broadband excitation from idealised sources. However, little attention has been paid to include the vibratory strength and power input from real machinery sources, although such data are required for an absolute response prediction. One apparent reason is that the actual characterisation of vibratory sources is still in a development stage, and there is no standardised method for measuring the vibratory strength of machinery sources. This fundamental problem has been addressed, and a new method has been proposed for characterising multi-point connected sources. The overall strength of a source is determined by the sum of absolute values of its terminal complex powers. From results of the present investigation this method appears to be well suited for input power predictions in SEA. From an approximate estimate of the averaged source energy this study has furthermore revealed that there is a simple relation between the averaged coupling quantity used in a deterministic prediction of power transmission and the coupling loss factor commonly used in SEA.
|Effective start/end date||01/01/1997 → …|