Study On Measurement Methods And Techniques Of Experimental Mechanics Based On The High Spatial Resolution Imaging Systems

With the rapid development of micro-and nanotechnology, it's necessary to research the new experimental methods or techniques on micro/nano scale. In this thesis, some new measurement methods and techniques of experimental mechanics are studied, which based on the high spatial resolution imaging systems. Three micro scale measurement methods have been developed, which are array microindentation mark method, speckle microinterferometry and crystal grain deformation analysis (CGDA). The array microindentation mark method employed digital microscopic system and micro/nano marks to measure the microregion deformations of the tested samples. The measurement system has been constructed and the microregion deformation extracting method, the feasibility, as well as the measuring performance of the array microindentation mark method were also discussed. Optical full-field techniques for measuring deformation on micromechanical components are studied. A Linnik speckle microinterferometric system is designed and constructed. Optical performances and applications of full-field optical measurement methods used in our system are investigated. In this method, the measurement range of the ESPI technique is extended to the scale of several micrometers, and the TSPI technique is also applied to the micro scale measurement. Based on the scanning microscopic platform, a new deformation analysis method, CGDA, has been developed. Applied this method, the evolvement of the grain deformation and interactions can be obtained. Furthermore, based on the developed measurement methods and techniques, some experiments have been carried out. The first experiment is microregion deformation measurement of thin films by array microindentation mark method. The deformation in the vicinity of a microcavity defect on the film surface was measured. The array microindentation marks are indented using a nanoindentation machine and the microcavity defect is produced by the micro-electrical discharge machining (micro-EDM) technique. The second is deflection measurements of microbridges. Microbridges of Cu films and NiFe films are investigated under static and dynamic loads in the microinterferometric system and ESPI and TSPI methods are employed to demodulate the film deflections. Young's modulus of the Cu and NiFe films is obtained. The experiment results are also analyzed by the different theoretical models. The final experiment is the grain deformation and interactions measurements in an Al alloy multicrystal. Evolvement of deformation in grain-scale is obtained by extracting the deformation of grain boundary.