Normal modes of the elephant bell

The normal modes of a 16-tine elephant bell have been investigated using finite-element modeling, group representation methods and electronic speckle pattern interferometry. The experimental results are in good agreement with the model for about the first ten frequencies, and both are consistent with the predictions of group theory. It is found that the vibration spectrum can be understood by regarding the tines as a set of identical oscillators coupled in series in a closed loop with the hemispherical crown holding them in place, providing the coupling and, perhaps, acting as a sounding board.