Ballistic Impact on Concrete and Asteroid Collision with Minerals Show Striking Commonalities
摘要
This study investigated projectile impact on concrete targets and analyzed the characteristics of the debris ejecta. Concrete cylinders (6 kg) were impacted with 10-mm diameter steel ball bearings (4 g) at impact velocities ranging from 250 to 1150 m/s (i.e., specific energies from 0.02 to 0.44 J/g). Ejected debris was recovered and its particle size distribution (PSD) was analyzed using a power law relationship to identify a correlation between impact velocity and PSD. The results align with damage models applied in studies of asteroid impacts into natural rocks and minerals with similar specific energies. Specifically, when the impact event created significant disruptive damage to the concrete target, the PSD power law exponent was < 2.5, but when the concrete target damage was localized (semi-infinite), the PSD power law exponent was ~ 2.5. Despite the composite nature of concrete, under extreme loading conditions concrete exhibits similar debris characteristics to geological studies of natural rocks and minerals that align with established damage models.