INPLANE ELECTRONIC SPECKLE PATTERN SHEARING INTERFEROMETRY

An analysis of the out-of-plane shearing interferometer has been perfo rmed which shows that production of in-plane strain partial derivative s is possible, which are not affected by out-of-plane displacement fun ction components. The in-plane data are represented as subtraction cor relation fringes. This interferometer employs a single diverging illum ination beam and is applicable to object plane stress and plane strain loading conditions. The interferometer was tested and compared using a compact tension crack specimen and the results are correlated with f inite element software predictions of strain distributions across mode lled specimens. This experimental validation was chosen because we had an existing test rig and finite element models which had been indepen dently verified. Copyright (C) 1996 Elsevier Science Ltd.