UBC Theses and Dissertations
Vibration analysis by holographic interferometry Liem, Sing D.
Holographic interferometry offers tremendous potential in the analysis of small amplitude vibrations of three dimensional objects. Due to stability requirements and the necessity of a coherent light source, the analysis is still limited to the laboratory. In this experiment the various holography systems for vibration analysis developed to date were investigated. Secondly, a real time holographic interferometry technique was developed for quantitatively mapping the complete dynamic field of a surface, where the amplitudes of vibration are on the order of the wavelength of light used. This technique offers the following features: (a) The phase of the object can be determined. (b) The exact resonant frequency can be pinpointed by observing the phase change of the vibrating object (c) Entire displacement fields can be determined, even though the maximum amplitudes of vibrations are on the order of only a few microinches. (d) Under continuous illumination the mode shape of the object can be readily observed.