Determination of mechanical vibration properties of one-dimensional structures using a fringe projection method

This work is concerning with the use of the fringe projection technique to determine amplitude and frequency of a vibrating one-dimensional structure. Fringe projection on to a flat fixed end large cantilever, plastic made, excited mechanically by means of a loudspeaker is studied. By means of a CCD camera, images of the projected fringes are registered and subtracted to video ratio. As a result, a moiré pattern is obtained and seen on a monitor screen. It is shown that the vibration amplitude is obtained from the period of the moiré pattern, and the frequency by means of the synchronization (triggering) of the moiré images. The future of this investigation is to apply this technique to electricity transmission lines.