<title>Transient bending wave analysis by Fourier evaluation of single-pulsed TV holography fringe patterns</title>

Abstract

In this paper we demonstrate the feasibility of impact-induced transient deformations measurement by singlepulsed subtraction TV holography and the Fourier transform method with contouring fringes as spatial carrier. Fringe formation in single-pulsed subtraction TV holography and phase demodulation by the Fourier transform method are described. Contouring fringes are probed to be well suited for introducing spatial carrier in the correlation fringe patterns. Experimental results are presented. Finally, the degree of immunity to environmental disturbances of this technique is discussed and improvements are proposed.

A systematic approach to TV holography

“…In this variant, the carrier is introduced through the changes of the object phase difference φ o (x) tilting the illumination beam between exposures; this tilt being symmetrical with respect to the observation direction (section 3.3.3), it is equivalent to a degenerate shape-measurement technique in which the contouring planes are parallel to the observation direction and produce a set of equally spaced parallel fringes that is used as the spatial carrier. The change of the object phase difference among exposures can be expressed as This technique has been demonstrated with secondary PM correlograms for contouring [249], shearing [250,251], out-of-plane [152,252] and in-plane [253] geometries.…”

“…This technique has been demonstrated with secondary PM correlograms for contouring [249], shearing [250,251], out-of-plane [152,252] and in-plane [253] geometries.…”