Holographic strain analysis: an experimental implementation of the fringe-vector theory

The fringe-vector theory of holographic strain analysis was applied experimentally to determine strain and rotation tensors of rotated and deformed objects. One object was supported in a specially designed positioner, and the other was heated internally with a temperature controlled device. The rigid body motions and deformations were determined directly from the fringes that were observed on the surface of the object. This was done by taking photographs of the virtual image of the object from several different directions through the same hologram; the photographs were digitized manually, and the parameters obtained were, in turn, analyzed using a computer. The strains and rotations determined experimentally from holograms compared satisfactorily with the theoretical ones.