Abstract: A mathematical model is built for imaging of electronic shearography. Based on the model, the computer simulation software is developed, which can produce different shearographic fringe patterns with different system configurations and/or different deformation. With the help of the software, the influence of shearing distance on fringe pattern of shearography is studied. The results don’t agree well with classic theory of shearography, so called “displacement derivatie” theory. Theoretical analysis and experimental results show that the simulation results are correct. A new way for interpretation of shearographic image, theory of “twin points’ displacement difference”, is presented. The research work is valuable for design of shearographic NDT system and analysis of inspection results.

Key words: Computer simulation, NDT, Shearography