STRUCTURE-BORNE SOUND TRANSMISSION FROM MACHINES IN BUILDINGS, PART 2: INDIRECT MEASUREMENT OF FORCE AND MOMENT AT THE MACHINE-RECEIVER INTERFACE OF A SINGLE POINT CONNECTED SYSTEM BY A RECIPROCAL METHOD

✍ Scribed by S.H. Yap; B.M. Gibbs

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 313 KB
• Volume: 222
• Category: Article
• ISSN: 0022-460X
• DOI: 10.1006/jsvi.1998.2047

✦ Synopsis

There is increasing evidence that moments are signi®cant contributors in machine induced structure-borne sound. Omission of these components in prediction can therefore lead to an underestimate of total power in some cases, although it is recognised that considering all transmission paths in prediction generally is not a practical approach, due to the complex nature of the problem. A way forward is to establish the installation conditions and the primary transmission paths and components in order that the least important can be neglected for simpli®cation in the prediction. To permit the measurement of force and moment at machine contacts, the indirect method described in a companion paper (Part 1) was employed. Experimental results for a machine attached to a concrete ¯oor and a brick wall demonstrate that the contribution of moment components is sensitive to source location. At low frequencies, moments are less important than vertical forces when the source is away from the structural discontinuities such as ¯oor edges. However, moments are important at low frequencies when sources are in the proximity of structural discontinuities. Moments have an increasing contribution with increased frequency irrespective of excitation location.