5pMU7. Vibration analysis of a glass harp by a finite-element method: Minor pitch change due to localized shaving of the bottom part.

Session: Friday Afternoon, December 6

Time: 3:30


Author: Takuji Nakanishi
Location: Dept. of Elec. Eng. and Electron., Faculty of Eng., Osaka Sangyo Univ., 3-1-1 Nakagaito, Daito Osaka, 574 Japan
Author: Ichiro Nakai
Location: Dept. of Elec. Eng. and Electron., Faculty of Eng., Osaka Sangyo Univ., 3-1-1 Nakagaito, Daito Osaka, 574 Japan
Author: Atsushi Yarai
Location: Dept. of Elec. Eng. and Electron., Faculty of Eng., Osaka Sangyo Univ., 3-1-1 Nakagaito, Daito Osaka, 574 Japan

Abstract:

The finite-element method (FEM) was applied to analyze the vibration (inherent and the harmonic frequencies) of wine glasses (glass harp) as a musical instrument. FEM analysis for this problem was proven appropriate by confirming the coincidence between the experimental and analyzed inherent frequencies for several glass cups with different shapes. When using wine glasses as musical instruments, minute arrangement of the pitch is necessary. Even today, this is done by filling a certain quantity of water in the wine glasses. This method, however, is very troublesome because each time, just before a performance, a check has to be made to confirm that the correct water quantity had been filled in every vessel. Compounding the problem, the pitch sometimes changes during the performance because of water evaporation. In place of this water-filling method, minute pitch changes have been achieved by locally shaving a bottom part of each vessel. The pitch is found to decrease in proportion to the shaved glass quantity. The relationship between the shaved glass quantity and the changed pitch has been clarified experimentally and analytically through FEM analysis. With this procedure, the desired pitch can be obtained.


ASA 132nd meeting - Hawaii, December 1996