Performance of optical speckle displacement technique near stress concentrators

The optical speckle-displacement correlation technique was developed to increase the reliability of surface displacement field recovery near stress concentrators. The performance of optical speckle correlators based on joint transform correlator (JTC) architecture and a joint power spectrum nonlinear filtering (median thresholding, adaptive median thresholding, ring median thresholding) is studied by using computer models of these correlators. The design of hybrid joint transform speckle correlator is detailed. Example results of correlation signal using computer models of digital speckle correlation and optical speckle-displacement correlation techniques and created hybrid joint transform speckle correlator setup are described.