| Frequency domain analysis of deformed micro— grids is presented and realized in this paper. Frequency domain analysis, which is one of the most important techniques in modern signal processing field, is utilized to extract deformation data from the microscopic images of deformed micro-grids. The mathematical derivation of the extraction procedures in this paper founds the theoretical basis for the development of a real-time measurement method in the experimental researches of micromechanics. Furthermore, an opening interface is proposed to continue to take advantage of new technical achievements of interrelated subjects.An automated system of micro-grids using digital image processing and frequency domain analyzing techniques is established in this paper. By developing fast and efficient algorithms for two-dimensional discrete Fourier transform and matrix transposing of microscopic grid images, and by designing the frequency domain analysis software with a clip window in frequency domain, the deformation data are extracted from microscopic grid images automatically, whole— fieldly and with fast processing speed. Meanwhile, the separation of displacement fields and the multiplication of micro-grids have also been realized simply and conveniently.Zero—thickness micro-grids are successfully fabricated within a tiny area of the material surface which contains microscopic flaws. The technique of using a rotating point source to obtain high quality holographic gratings and some fine machining techniques such as lazer machine are utilized. The deformation informations in microscopic areas of the material are transmitted quantitatively in real-time and free from the unfavorable influences of shearing retardation effect and strengthening effect. The presented zero-thickness micro-grids make it possible to monitor the developing process of microscopic structures under quasi—static and dynamic loads and various temperature conditions.
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