Use of Holographic Fringe Linearization Interferometry (FLI) for Detection of Defects

摘要

This final report shows that the two-exposure FLI holographic method is feasible. We describe how the two-exposure FLI technique can be utilized by increasing the linear fringe frequency. Reprints of the published papers from this contract describing the modeling/experiment program are appended. The feasibility of an automatic readout for the linear fringe method is demonstrated by showing that observable and measureable effects at the defect site can be monitored. The sensitivity analysis and results from a simple dynamic loading model are presented. A preliminary FLI experiment on composite samples with both static and thermal loading failed to find defects. Finally, recommendations of work necessary to develop the FLI technique are given. Keywords: Holographic interferometry; Non destructive evaluation; Lasers; Moire techniques; Finite element analyses.