Introduction: Impacts initiate dynamic fracturing on macro-and micro-scales, and the resulting fragmentation can be related to strain rate. The dynamic fracture process has been directly observed at low strain rates (~10-2 to 10-3 s-1 , during earthquakes) and at high strain rates (~10 5 to 10 6 s-1 , during laboratory-scale hypervelocity impact experiments) [1]. Based on first order estimates ...