Investigation on high-velocity impact of micron particles using material point method

• We study the influences of impact angles and velocities of single micron particle.
• There are four crater morphology modes in normal impact of particle group.
• There are seven crater morphology modes in oblique impact of particle group.
• An empirical formulae of crater depth versus normal impact velocity is proposed.

Continuous high-velocity impact of micro space debris and micro-meteroids may cause significant accumulative damages to spacecrafts. The process of high-velocity impact of micron aluminum particles on the aluminum target is investigated with the material point method (MPM). As a meshfree particle method, MPM is very suitable for solving high-velocity impact problems owing to its prominent advantages of dealing with fracture, fragmentation and moving material interface over the traditional mesh-based methods. The target plate is modeled as semi-infinite media since its thickness is much larger than the characteristic length of the projectile particles. The micron particles are projected to the target individually and in group with different angles and different velocities. The predicted impact responses and dimensions of the craters agree well with the experimental results and the empirical equations. The influences of the flux density, the projectile angle and the impact velocity are thoroughly investigated, and the morphology modes of the crater group are concluded. Finally, an empirical formula is proposed for the crater depth under impact of particle group.