A preliminary study of using high-speed digital image correlation (DIC) to characterize the penetration on geomaterial

The high-speed DIC has been widely applied to identify the mechanical properties and fracture behavior of the material at high strain rates. With respect to the penetration process in geomaterial, high-speed imaging is still restricted to be used to measure the initial and residual velocities of the projectile but rarely for damage assessment. The evaluation of impact damage is frequently achieved in the post way by visual inspection, ultrasonic or optical profilometry scan. This study explores the potential application of the high-speed 3D-DIC technology to characterize the real-time deformation and fracture during the projectile penetrating the geomaterial. A resolution of 512 × 512 and frame rate from 50,000 to 100,000 were adopted to capture the deformation of the rear surface of the sandstone and gabbro. Three projectiles with different head shapes were implemented to impact the rock. The deformation and fracture pattern were revealed and discussed. The result showed that the high-speed DIC is a promising tool to investigate high velocity penetration in brittle material. Additional recommendations for the better achievement is presented at the end.