LAUSR

Digital image correlation (DIC) has inherent limitations in large deformation measurement, such as speckle pattern decorrelation and high computation time cost. A new dots pattern with fixed size and randomly distributed dots is devised for DIC, rather than the traditional grayscale speckle pattern. Topology-based matching correlation (TMC) based on dots pattern is proposed, in which topology connectivity property is used in correlation calculation for images before and after deformation. Experiments on simulated tensile deformation with up to 300% elongation and nitrile-butadiene rubber tensile tests with 260% elongation were designed and results showed that, compared with the incremental-DIC method, the proposed TMC based DIC (TMC-DIC) method could correctly obtain large deformation with no need of updating reference image, less time consumption and smaller errors. The proposed method also has advantages in the applications like real time deformation observation or deformation measurement of large-scale structure.