New Technique Based On Digital Image Processing In The Macro,Micro-scale And Dynamic Photomechanics

In this paper, a new method for four-beam moiré interferometry and a spectral phase algorithm applied to digital speckle image correlation are studied. And we also do some experimental analysis applying shadow moiré method to dynamic impact measurement of cantilever. Four-beam moiré interferometry is widely used as a powerful tool in the measurement of U and V displacement fields, In this paper, a new measurement method is studied based on this four-beam moiré interferometry method. We can analyze the strain of the whole filed directly using the change of the few carrier wave fringes. The principle of the new method is presented in this paper. And then we analyze its own precision using image processing and experimental technology. Justify that the strain precision is about 10 με when the strain is directly measured using the reflective crossed diffraction grating (specimen frequency 1200 lines/mm) in mm field. And the strain sensitivity can reach less than 1 με .The technology provides technical sustain for the analysis of correlative mechanics content in the research of MEMS. Fourier transform is an important transform in many fields. For this part, we combine the theory of Fourier translation to digital speckle image correlation, and develop a new method to the in-plane displacement measurement—the spectral phase algorithm. The principle is presented and the iterative formula is educed. We develop the program and use it to simulated calculations. Get a 0.06-0.1 pixel precision of displacement measurement when the interpolation is not processed. Finally, the moiré method applied to dynamic measurement is studied. Utilizing the shadow moiré method and high speed camera, we complete the capture and analysis of moiré images in dynamic impact measurement of cantilever. Develop the processing program to calculate the deflection of the whole field. Then compare with the theoretical value. Receive a satisfied outcome. As mentioned above, a new method base on four-beam moiré interferometry is developed. We can analyze the strain directly but not displacement. And then study the spectral phase algorithm applied to digital speckle image correlation, it can provide subpixel accuracy without need of the interpolation process. Finally we do some experimental analysis applying shadow moiré method and high speed camera to dynamic impact measurement of cantilever. Receive a satisfied outcome. We are very happy to see that the micro-scale and dynamic measurement of the solid experimental mechanics in the future can benefit from the research work.