Abstract
Image analysis methods based on the digital image correlation (DIC) for measuring strain distribution together with crack propagation in concrete are developed in this paper. The hierarchical modeling in the DIC is introduced to construct high resolution grids of measurement. The tracking of material points and the updating of displacement vector using finite element interpolation are also introduced to increase the accuracy of the DIC. We first show the detail of our image analysis method based on the DIC. After the validation test of strain is performed, we apply the present method to compressive tests of mortar specimen and examine how to detect crack propagations clearly. Finally, the present method is applied to concrete to visualize the complicated crack propagations due to coarse aggregates.
