Modes Of The Spiral Clock Gong

✍ Scribed by R. Perrin; T. Charnley; G.M. Swallowe; H. Banu

• Book ID: 102976167
• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 571 KB
• Volume: 162
• Category: Article
• ISSN: 0022-460X
• DOI: 10.1006/jsvi.1993.1098

✦ Synopsis

The modal frequencies of a spiral clock gong have been measured. The mode numbers and forms of vibrations have been identified by finite element modelling and photographic techniques; very good agreement between modelling and experiment was achieved. All modes were found to be either purely in-plane or out-of-plane. In both cases plots of (\log (2 n-1) v s . \log f) yielded curves with two distinct regions, the transition occurring where the wavelength corresponded to one turn of the spiral. Both sets of lower modes were very complex but the modal frequencies above (n=11) were found to fit a modified form of Chladni's law. It is suggested that the modified Chladni law may form the basis of many musical sounds.