Dynamic deformation field measurement system for rock failure and its application

A dynamic deformation field measurement system based on high-speed image capturing devices and digital speckle correlation method (DSCM) is established to measure the dynamic deformation of rock specimens. The principle and elements of the system are introduced. Among them, the choice of special light sources, the setting of the imaging acquisition rate and the triggering techniques for high-speed camera capturing are described as the key techniques for dynamic deformation measurement of rock. The dynamic deformation field measurement system can accurately capture the high-speed images and then obtain the quantitative deformation fields for a rock specimen subjected to either quasi-static or dynamic loadings. Two experiments, a Brazilian disc test and a dynamic mode-I crack fracture test, are performed to verify the feasibility and effectiveness of the measurement system. The quantitative dynamic deformation fields during the failure procedure of brittle rock obtained by the dynamic deformation field measurement system may provide solid experimental support for intensive study of rock failure mechanism.