Abstract:

Digital speckle and speckle shear pattern interferometry (DSPI and DSSPI, respectively), are two independent useful whole-field non-contacting optical methods for nondestructive flaw detection and precision measurements. In this paper, we propose a (5, N) phase shift algorithm, which is a modified version of (5, 1) algorithm adapted for quasi-dynamic behavior of objects subject to slowly varying loads. Quasi-dynamic variation of the fringe patterns due to thermal loading are recorded. Defects and their behavior in loading conditions as well as the deformations and/or its derivative maps can be monitored. Phase unwrapping software has been developed to generate the 3-D profiles. Experimental results on polymethyl methacrylate (PMMA) panels for quantitative non destructive evaluation are demonstrated.

Keywords: DSPI; DSSPI; FRINGE ANALYSIS; NON DESTRUCTIVE EVALUATION; PHASE SHIFTING

Document Type: Research article

DOI: 10.1166/jhs.2006.002