TORSIONAL DYNAMICS OF THE BIRNBOIM-SCHRAG MULTIPLE LUMP RESONATOR STUDIED USING TV-HOLOGRAPHY

We have studied the torsional dynamics of the Birnboim-Schrag multiple lump resonator (MLR) using TV-holography. The relative torsional displacement amplitudes have been determined for all resonator lumps at their five resonance modes. Due to the low vibration amplitudes for the highest frequency mode, we only give a rough estimate of the relative torsional displacements for this resonance. For some lumps, the observed relative displacement amplitudes deviate by as much as a factor of 2 from the predictions of the dumbbell theory commonly used to analyze MLR dynamics. The experimental data agree well with the recent theoretical analysis carried out by Mikkelsen et al. (1992).