Pseudo-Degeneracy in Handbell Modes

The vibrational modes of handbells exist in nearly-degenerate pairs which have been split by nonuniformities in the bell. The possibility of intentionally re-combining a pair into pseudo-degeneracy was explored by adding mass to various locations on a C4 handbell. Depending on the location and mass added to the bell, the modes can be shifted in position and frequency as observed by a real-time holographic interferometry system. By moving and varying the added mass, one pair of modes was successfully brought into a pseudo-degeneracy.