Whole field displacement measurements by holographic interferometry with application on sonic transducers

Holographic interferometry was used to study several sonic transducers. These transducers are shaped, circular (cross section) resonating systems driven by a sandwiched piezoelectric ceramic. The simple resonator, the P-7, and P-11 transducers were studied. The investigations were performed to accurately determine their dynamic system mode shapes. Holographic interferometry was used because it is a whole field, noncontacting measurement procedure. It was applied to achieve quantitative results in determining the two dimensional axisymmetric mode shapes. Holography was also extended by examination and evaluation of interferometric localization. Evaluation of the accuracy obtained with interference localization was accomplished with a statistically deflected cantilever beam. The heavy influence of fringe width was critical. Superimposed displacements were applied as a fringe sharpening device to improve results. Localization was also applied to the resonator for verification of its applicability to single hologram, two dimensional mode shape analysis.