可变形异型弹体撞击高强度岩石实验

Fracturing a high-strength rockto collect the fragment samples by the kinetic energy of deformable special-shaped projectile has attracted much attention in the Near-Earth Asteroid (NEA) sampling scheme. Three types of deformable special-shaped projectiles,i. e., petal penetrating, petal non-penetrating and oval penetrating, are designed to study theprojectile-target interaction and rock fracture mechanism. Based on 57 mm lightgas gun and 14. 5 mm ballistic gun, the low-speed (71. 4 - 280. 0 m / s) and high-speed (453. 0 - 612. 0 m / s) impact experiments are carried out for a rock with uniaxial compression strength of 180 MPa to obtain the reflected velocity of projectile, mass of rock fragments, and diameter and depth of fracturing zone. Experimental results show that, in the low-speed impact experiments, two types of petal projectiles have lower reflected kinetic energy ratio and its reflection speed is reduced by 21. 9% - 42. 8% compared to other projectiles; In the high-speed impact experiments, the projectile-target interaction of petal projectile is two-phase processes: multi-point simultaneous impact and Taylor rod impact, which increase the mass of fragments about three times than petal penetrating projectiles. The research inspires the designing of deformable special-shaped projectile and the comprehending of fracture mechanism of rocks under impact.