The physics of protoplanetesimal dust agglomerates. VII The low-velocity collision behavior of large dust agglomerates

摘要: We performed micro-gravity collision experiments in our laboratory drop-tower using 5-cm-sized dust agglomerates with volume filling factors of 0.3 and 0.4, respectively. This work is an extension previous reported Beitz et al. (2011) to aggregates more than one order magnitude higher masses. The consisted micrometer-sized silica particles were macroscopically homogeneous. measured the coefficient restitution for velocities ranging from 1 cm/s 0.5 m/s, determined fragmentation velocity. For low velocities, decreases increasing impact velocity, contrast findings by (2011). At value becomes constant, before break at onset fragmentation. interpret qualitative change as transition a solid-body-dominated granular-medium-dominated behavior. complement molecular dynamics simulations porous obtain reasonable match experimental data. discuss importance protoplanetary disks, debris planetary rings. extensional study group gives new insight velocity dependency due improved measurements, better statistics theoretical approach.