Applications of Holography to Dynamics: High-Frequency Vibrations of Beams

Abstract

The relatively new experimental technique of holographic interferometry is described, and time-average holography is discussed. Time-average holography has been applied to study high-frequency transverse vibrations of a uniform cantilever beam. Modes from the 5th through the 34th were identified and recorded on holograms, the corresponding resonant frequencies ranged from 500–25,665 cps. In addition, the 77th mode was recorded at 99,395 cps, which demonstrates that the technique is workable at frequencies on the order of 100 kc. The experimental mode shapes and frequencies show good correlation with the Timoshenko beam theory. Other applications of holography to dynamics are briefly discussed.