Electronic speckle pattern interferometry, electronic shearography, and their applications

Advances in computer and electronics technologies have brought new life to traditional film based holographic interferometry (HI) and shearography. As a result, the electronic versions of HI and shearography, called electronic speckle pattern interferometry (ESPI) and electronic shearography (ES), have been developed. These developments greatly reduced the rigorous stability requirement and the tedious and slow information processing procedures. Consequently, they have led to a real opportunity for more and more applications in the industrial and scientific worlds.; This paper contains a comprehensive and systematic discussion and analysis of the techniques of ESPI and ES systems and their engineering applications. The effect of the sensitivity vectors on the accuracy of the measurements is analyzed for various cases. A loadingless NDI method and a complementary NDI approach are proposed. Some experimental techniques and results on nondestructive evaluation (NDE) of fiber reinforced plastic (FRP) composite structures and other engineering applications are presented.