Flaws detection in a partially-clamped plate using comparative DSPI

Abstract

The paper presents a method to determine defects on a partially clamped plate using comparative digital speckle pattern interferometry (DSPI). The flaw locations are determined using fringe compensation. In flaw detection of a partially-clamped plate which contains a centric flaw, overcrowded fringe pattern is often a problem encountered and it is difficult to locate and size the flaw since no perturbation of the fringe pattern is observed. When fringe compensation is applied, the overcrowded background fringes are removed leaving only fringes indicating the defective region. The results in this study show that the proposed method is effective in detecting both the location and size of the defects. Partially-clamped square plates of sides 80 mm which contain centric circular flaws are loaded by incremental pressure and the results show that comparative DSPI is capable of flaw detection. Theory of the method and experimental results are presented.