Damage Characterization of Granite under Hypervelocity Impact

Granite is the most common crustal rock and is often subject to extreme dynamic loads, such as earthquakes, meteorite impacts, and underground explosions. A quantitative understanding of the connection between the microstructure of granite and its behavior under extreme pressure and loading rate would assist with the assessment of the effects of events such as planetary impact. This work reports the results of high-velocity impact experiments of metal spheres on Westerly granite at velocities of 1 km/s to 3 km/s. We assess the size and shape of the impact craters as well as the distribution and velocity of ejecta. To characterize damage beneath the crater, we section the material and map the size, shape, and distribution of defects using high-resolution X-ray computed tomography. The 3D damage distribution in relation to the hypervelocity impact will be discussed. These results contribute to a better understanding of damage under impact craters on planetary surfaces and the structural response of granite in real-world applications.