Effect of deformation of a flat plate specimen under in-plane blasting loading on 2D and 3D digital image correlation measurement.

In combination with high-speed photography, a 3D digital image correlation (DIC) experimental system suitable for an in-plane blasting experiment is established to effectively explore the mechanism of blasting. The dynamic response of the specimen under in-plane blasting loading is analyzed on the basis of the model experiment, and the effect of out-of-plane deformation on the 2D-DIC measurement under a blasting stress wave is studied. First, the out-of-plane displacement and strain evolution law of the specimen under blasting load are studied by using a 3D-DIC system. Second, an analytical model of the effect of out-of-plane curved displacement on 2D-DIC measurement under the blasting load is proposed on the basis of pinhole imaging theory. Finally, the specific error value and error percentage of out-of-plane displacement to the 2D-DIC measurement results are quantitatively analyzed on the basis of the established theoretical method. Results show that the theoretical error of out-of-plane curved displacement to 2D-DIC accounts for 10.8% of the measured vertical strain. In the polycarbonate plate specimen, the effect of out-of-plane displacement caused by the blasting experiment on 2D-DIC measurements cannot be ignored. This novel, to the best of our knowledge, experimental system provides a wealth of experimental data, including in-plane full-field strain evolution and out-of-plane displacement changes.