| The digital image correlation method is a non-contact measurement for full-field deformation of the object surface, which is based on image gray information,computer image process technology application and making comparison of the image gray information of the surface before and after deformation. Compared with traditional deformation measurement methods, it has been widely used in experimental mechanics and other fields due to its advantages of non-contact, simple operation, environmental adaptability, and high accuracy.This paper has carried out the following research work:1. Firstly, this paper introduces the basic theory of digital image correlation method and the fundamental principle of binocular stereo vision system. Then, the three dimensional digital image correlation (VIC-3D) measurement system is used based on the digital image correlation method and the fundamental principle of binocular stereo vision system. Besides, the factors that can influence the precision of the measurement system is analyzed by experiment, and the optimal calibration numbers and optimal sub region size are obtained. Finally, the axial tensile experiment of cast aluminum is applied for verifying the accuracy of the system.2. In order to realize the measurement of cylinder surface topography, this paper proposes two topography splicing methods. Besides, two new methods of acquiring cylindrical surface characteristic parameters is proposed for discrete points of the cylinder structure surface, including intersection curve method and cylindrical surface fitting method, and the reliability of the method is verified by experiments.3. Surface topography and mechanical properties of the large diameter thin-walled cylindrical shell with appearance defect are measured by using the VIC-3D measurement system. And the experimental data and the finite element calculation results are compared and analyzed, so as to verify the accuracy of the finite element method. |
PDF Full Text Request