Microscopic Digital Speckle Correlation Measurement System Design And Research

For the sake of the need of evaluating the health of bridge, a measurement system of double-micro Digital speckle correlation method was developed, based on understanding of domestic and foreign research and application condition of digital speckle correlation technology. The measurement system has been used to measure distortion of PMMA, which provide a basis for evaluating the safely of bridge.This paper is completed mainly with chapter four. Firstly, the theory of digital speckle correlation was discussed and the measurement system of double-micro Digital speckle correlation method was developed.Secondly, hardware components and principle of the measurement system were introduced. Optic-design of object lens with microscope, CCD, image-collect card and other relational operation were completed.Thirdly, zero-floating experiment and displacement of rigid body experiment were studied, to test the capability of the system. Errors of measurement system have been analyzed in detail. And some methods to reduce these errors were proposed.Fourthly, the measurement system was used to get the elastic modulus of PMMA through the loading measurement of tensile test, and then was compared to the electromotive result. The result proves that the measurement system in this paper can be applied in the healthy safe monitoring of the bridge project.Finally, the main achievements of this thesis were summed up and direction of further developing in this field was point out.