Measurement of transient deformations by means of pulsed TV holography

KAUFMANN, G.H.; DÍAZ, F. V.

LATIN AMERICAN APPLIED RESEARCH

PLAPIQUI(UNS-CONICET)

Lugar: Bahia Blanca; Año: 1998 vol. 28 p. 181 - 186

0327-0793

This paper describes a pulsed TV holography system for measuring high speed transient displacement fields generated over the surface of a test object under impact loading. Two separated speckle patterns produced by a ruby laser which freezes the object motion are recorded using a TV camera and stored in a frame grabber. The computer used for image processing is also utilized to control image acquisition. The electronic and software control devised to synchronize the laser pulses to the TV camera and the object position is described. Transient displacement fields are determined by digital analysis of the fringes generated by the subtraction of the recorded speckle patterns. As an example, the in-plane displacement field generated by the impact of a pendulum on a steel cantilever beam is presented.